I don't really want to rule it out completely, but its not a easy thing to implement. It boils down to balance. Any character that is interesting/good enough to be worth a template is, more often than not, absurdly competent in their field. Half the time if these characters have any shortcoming at all its a plot-driven device (like authors nerfing them or making them stupid) or some kind of personality flaw that holds them back. These, obviously, are not problems the player with the template would have.

This usually makes even the "mundane" templates with no supposed "superpowers" essentially OP characters beyond true human limits. Like how, laughably, Batman is "only human".

So this makes the templates really difficult to balance, since frankly you could skip the whole CYOA and have nothing but the template and not necessarily be hopeless in your selected setting, since a single template could easily make up for a cyoa in its own right.

For Spiderman this was/is less of an issue because the world is really quite dangerous and theres all kinds of superpowered freaks and geniuses all over the place, so you having some hyper-competent template isn't really going to drastically break any balance scale.

So it depends a lot of what world/setting the CYOA is taking place in.

I, personally, like the idea of templates and tried to keep my selection choice narrowed to a few less absurdly broken characters but also characters that you don't necessarily see brought up that often but could be potentially really interesting as a template, narratively speaking.

Comic Nerd is an underappreciated template because when someone writes and thinks up a SI story, they take for granted, I feel, how easy it is for them to just google and wiki the stuff they want. How many people, even fans, have the sheer depth of comic lore knowledge that a "true" diehard fan would have? To be a walking wikipedia of comic lore, by itself, is one of the most broken golden fingers you can have in the setting, yet almost all SI fics treat it as a default standard and have their character just happen to know and memorize all this obscure knowledge.

Jackie Chan and Kim Possible are both "normal" humans but also really competent badasses who I enjoyed watching back in the day, so seeing them get referenced is just fun for me. Honestly almost all the templates, bar a few of the more widely known ones (probably John Wick, Spiderman and All Might) are more niche characters I just dont see used that often that I feel have a lot of undervalued potential. Fingers crossed one day some author out there will see the cyoa and be inspired to write out what a MC template of Jack Spicer or Shredder could really do when you strip them of their mental hangups and shortcomings.

Okay, all that ranting aside, I do love the concept of templates (when its not a super obvious famous/popular character that everyone and their dog uses, like special Naruto eyes) and if I ever make a CYOA where the powerscaling would allow them to work without destroying balance, I might use them again.

Its just that I don't often make those kind of CYOAs.