I think one of the tricky things with iNat is that there are so many people and opinions involved and that it covers the entire world, which makes things that much trickier. There probably should be review criteria met before any change happens on iNat and maybe a mandatory waiting period between when a change is proposed and happens to allow for debate.
Speaking from my experience on taxonomic work, it’s pretty hard to make some decisions but decisions often have to be made. I’m a field botanist that does mostly conservation related work but I took a detour to play around with taxonomy with a genus that was lumped so badly that the majority of taxa with a conservation rank were lumped, which is very problematic for managing them. From the standpoint of the uber-lumper who made the mess, I did a lot of splitting/unlumping. From the standpoint of past splitters, I did some lumping and some splitting. It is worth noting that the lumper said that what the splitter did is just as justifiable as what he did. If the lumper had recognized the same taxa as the splitter but just made many of the species into varieties or subspecies, I don’t think it would have been a big deal as the boundaries between the ranks are often subjective and wishy-washy.
I used varieties (generally equivalent to subspecies) to denote taxa that appeared to be closely related (usually formed a single clade), were often geographically adjacent, were often mostly morphologically distinct, and appeared to possibly be diverging from a single taxon. Essentially varieties and subspecies are taxa well on their way to becoming species. I also used varieties when more research was needed rather than making a hasty decision. Some of my varieties are polyphyletic species but the DNA evidence isn’t solid on those and may never be as nature is messy. Arguably, everything I treated as a variety could justifiably be treated as a species and someone may put them back to species rank as some point if there is good evidence for it. Keeping some at variety for now, makes it easy for people to just ID to species when necessary. The reality is that that may just be a temporary stage for some taxa while waiting for evidence to confirm they should be species. One species in particular has evidence pointing to the likelihood of it being multiple morphologically similar species.
I completely lumped three taxa as the DNA results weren’t clear (and one presumed extinct I didn’t have fresh DNA for) and I couldn’t make a key that worked, but I recommended future research on them and they may be split back out at some point.
I described four new species. Three of these were just obviously morphologically different, so no controversy there. One was a cryptic species though. It is sometimes very difficult to tell it apart from what I split it from but it is geographically distinct and the DNA says they are not even closely related. I also took a variety of one species and brought it back to the species rank as it was again not closely related in the DNA, it was geographically distinct, and had its flowering phenology shifted about a month from the rest of what I split it off of.
I should note that all the clear species in this genus form hybrids with other clear species where they make geographic contact. That is just the messy reality of many plant species. That said, with this genus, you can ID most plants just based on where they occur as very few overlap geographically. There are also areas that just appear to be hybrid messes or maybe incipient species. I just call those intermediates. And the most wide-ranging species is ridiculously variable morphologically, which causes a lot of confusion, but all the evidence is solid that it is a distinct species.
The bottom line is that I wrote a treatment that followed the current evidence as well as possible and tried to make things as usable as possible for field biologists as I am one. That said, I had to write a geographically based key as many morphological characters overlap between taxa and it is only the combination of many of these that distinguish the taxa. Most are easily distinguished by gestault and where they occur, but you may need to measure the trichomes down to the nearest 10th of a mm to key them. They are still way easier to ID than many bryophytes though, which should be considered as much in ecology as large easy to ID plants.
While my work may be different than others, I would assume most taxonomist are trying to sort things out to the best of their ability and make something that is useful to other people. Like me, some may just have to put out a best guess on some taxa until a future researcher can sort it out. Hopefully they note this in their work. And in many cases, things are just really messy and there is nothing anyone can do about it. I think most people doing taxonomy are just chipping away at the many messes from either lack of data or technology to sort out the questions properly in the past, or cleaning things up from the more excessive lumpers and splitters, who in many cases thought they were doing right but didn’t have the necessary data to make good decisions. Sampling is everything and, if you look at the sampling of many (maybe most) scientific studies, it will baffle you that they could actually publish it. People only have so much time and money though.
Some people give species more weight than subspecies or varieties but anything with a name can be protected as far as I know. Animals can even get special population protection but that’s not likely to happen for plants without a name. Where lumping becomes bad is when a rare taxon is totally subsumed into a common taxon or multiple rare taxa are combined to become one common taxon. Just changing from species to subspecies or variety doesn’t matter a whole lot from the standpoint of laws as far as I know.
Why did I split off the cryptic species I did in my treatment? They aren’t closely related and they don’t occur near each other. If I didn’t have DNA evidence showing they were not closely related, I probably would have described it as a new variety rather than a species. Let’s say they grew together, which is where it would be more problematic for a field biologist. If they were subspecies or varieties growing together, that means they are closely related and probably would be hybridizing and just turn into one thing. So, if growing together and remaining distinct phylogenetically, they would probably be distinct species even if they are morphologically similar unless they diverged elsewhere and came back together with reproductive barriers. There are of course all kinds of other messy options (polyploids) and the reality of the relationships of many plant taxa is that things are very messy. For the not so messy situations where taxa are morphologically cryptic though, if two taxa that look very similar are much more closely related to other clearly distinct species, then it makes sense for them to be species and not subspecies.