SDL3 has been around for 1.5 years. I can't help but wonder about the choice of SDL2 over it. I started using SDL from its 3rd version. Don't I know about some advantages of SDL2?
The changelog for this project dates back to 2019, well before SDL3 was available. SDL2 supports some older platforms that SDL3 has deprecated. If you value running on those deprecated platforms and/or you don't need any of the features introduced since SDL3, it's quite reasonable to stick with SDL2.
Not sure when the switchover happened, but IIRC I started out with SDL2 on Homebrew and recently got this compatbility shim instead when it updated: https://github.com/libsdl-org/sdl2-compat
I don't have an extremely high opinion of sdl2-compat specifically because my SDL2-based projects have had several bizarre bug reports which originated in downstream packages presuming they could use this "compatibility layer" instead of the actual dependency I develop and test against.
The first version of the FT2 clone was released 7 years ago.