I just wanna bring up, even if you stick with the vibe of only really being into the really really cool/high tier mods, there's at least a few that are being made and are showing active progress(rather than either being demoed outside of the forum, or going silent and then suddenly showing up on release) that make me feel like "Nah, it's not dead yet".
There's SONIcsez1234's
Emerl character mod, which I actually had quietly dismissed at first, I mean, who's gonna code AND sprite pretty much every Special attack from Sonic Battle? Surely this is someone's random fantasy dream mod idea that doesn't take off beyond a few sprites and a list, right? But that one's going at a rather healthy pace and has previews for abilities and for sprites going on quite regularly!
It's not as much in the way of custom sprites, but I.-p's
NES Mega Man mod is also looking quite fantastic, lots of subtle details that make it feel on brand and Mega Man in general should make for a very different SRB2 playthrough, even ignoring the fact there's custom bosses in the mix somehow.
All this is ignoring other stage and character mods I've not kept up with, be it the super fancy ones or the up and coming ones, I'm just biased towards these two robotic faves. (one of my favorite Sonic characters and one of my favorite non-Sonic franchises)
Of course, "SRB2 Modding is not dead, in my opinion" is different from "SRB2 Modding hasn't put out much fresh that I'm into" so I get that this doesn't quite help your issue there. Don't let yourself get burnt out, you can either mix up how you're playing, or just go onto something else til you get that twinge of wanting to do SRB2 again, then the old stuff feels fresher and new stuff may have popped up!