GW has always been big here in the States in the table top community. I have never had to try hard to find a store to buy stuff although an actual GW store for me is a new concept. In fact, even deploying to different parts of the country for missions I would typically bring a small numbered force to get a game in pretty much expecting there to be somewhere nearby to play and have never been disappointed. I can drive 45 minutes and be at 7 stores including the one actual GW store(that I rarely go to) on a Saturday during normal times(ie not covid) and expect to be able to get a pick up game. It is the game store standard game for in store gaming. That said, he was asking about RPGs and Warhammer 40k isn't an rpg. It has that fantasy flight game based off of it but those never really got off the ground anywhere I have been although maybe there is a thriving at home community playing it I just never heard of.