kobolds need some love

Protogen?

More avali.
They're small so rarely get to have anything even smaller to play with

I guess it depends on how you rate them and which group. Overall, Avali are likely the least known overall as their popularity only really started to pick up around 2017-2019 and especially through the 2020's thanks to VRChat. Then Protogens, then Kobolds would come after that if you're counting everything that's ever included their species.
Given how Kobolds are mythological creatures, you could argue that most works containing them could be appreciated by furry-specific Kobolds and in general I'd imagine most people have heard of them before the other two. You're really only going to see a lot of Protogens and Kobolds among younger furries as the new generation seems to have a preference towards original species rather than utilizing real world ones. (Though I have no data to back this observation.)

So if we're just looking at what's most popular as of late, the order I'd say flip a bit, but even that could be argued because things like board games including Kobolds have come out where other venues for the other two have not.
The other two have also been limited in a way by creator's (un-enforcable) copyright holdings (which are within the creator's rights) which could reduce their "expanse" so to speak. The Avali are now much more open, but last I heard, Protogens were technically still a closed species, even if no one respected that.

Those are like, some of the 3 most overrated ones XD

snrk yeah, but they barely have any size art!

I'm not a patron, but I want to weigh in with my own 62 cents anyway.
1. [best]Kobolds
2.Avali
3. Protogen