As far as quantity is concerned, I believe either approach is fine. But are you sure you’re asking yourself the right question(s)? Everyone has a different way of using iNat, but without wanting to judge anyone, I personally am not a great fan of the quantity approach. The question I always ask myself is not “how many”, but “why” and “what contribution” can this observation make to the iNat community and beyond. For example, among plants, I tend to post an observation with:
- a species new to me I’d like to learn more about (of course!)
- a familiar species in a new place which says something interesting about its distribution area
- the first/last flowering/fruiting etc. to document phenology
- a photo which illustrates a particular diagnostic feature clearly in the hopes it can be helpful to someone else in the future, and so on…
Or in the case of arthropods, another of my passions, it could be an interesting interaction, or behaviour…
Then as far as possible, I try and spend time over fully recording, presenting and uploading the observation to make it as useful as possible to others.
Finally (particularly since I also started some serious IDing for others)… I ask myself: is this observation worth the time and effort others will put in to ID it?
At the end of the day though, there is, of course, no right or wrong approach to how you use iNat, so whatever makes you feel good in your relationship with nature 
.