First, you can “fave” your own observations, but that only makes them come up higher in a search sorted by faves.
If a system like this is implemented (and I feel like this has been discussed before), I’d say let identifiers do the ranking and not whoever made the observation. I have definitely seen unidentified observations where I think, “If I knew the plants of this area, I’d know exactly what this is. Someone can surely identify this one.” I usually just mark those as having fruit or flowers or whatever applies so identifiers who search for observations with those will find it.