I haven't played in game stores and don't spend much time there, but my impression from looking at schedule boards that it's almost all D&D 5E with a much smaller subset of Pathfinder and OSR. Maybe the odd Starfinder game. D&D and or some variant of D&D. I think it's a self-fulfilling cycle: people know D&D and want to play D&D so people run D&D games in these places. People haven't heard of Savage Worlds or whatnot so don't know to ask for it or join a game if one is offered.
Your best bet is gaming conventions to play different systems.
Other game systems do get played, but in home campaigns among friend groups. Our group plays D&D variants (Pathfinder, 13th Age) far more than D&D itself and we also play Fate, Call of Cthulhu, PbtA, and a bunch of systems of my own devising. Some of us have been playing together for 30+ years and we started with several non-D&D systems, so we always had a broad mindset when it comes to games.