If you're after a WW2 war sim with an enormous community that you can start playing with no financial outlay, though...
well, your demands are very specific, and War Thunder's your sim.
Sims differ from other PC games in that their raison d'être isn’t necessarily to entertain, at least not primarily. They’re not all best-sellers, but these are the titles with dedicated communties offering deep tutorials and incredible mods, that let you get as close to hauling a trailer full of plumbing parts across Europe, driving an F1 car, or piloting a military aircraft as national security laws will permit.
Perhaps the best thing about this air-and-ground combat sim is that it's very easy to just plunge into it, get a decent idea of its systems and start having fun right away.
You’re here because you want to know what the best simulation games for PC are right now. It is, however, fascinating, terrifying, and hugely satisfying as a long-form experience.