First and foremost, i'm not from USA, but from small EU country. I also lived in Germany (Munich),Austria (Vienna) and Italy (Milano). From personal experience, organised play just isn't big thing here. Even in game stores, people who do play, are mostly already formed friend/acquaintance groups that just need place to play ( although, in game stores, there are more MtG players than ttrpg players). Gaming conventions aren't really that numerous also ( USA has way more than whole Europe combined).
In my hometown (around 1 million people) we have 1 convention of sf/fantasy that has organised play. Most of people who play there know each other or at least have someone they know in common, which is mixed bag. If you have personal grudge with someone who is also gamer, there is good chance you will bump into each other, maybe even be in the same game. When it comes to stores (really, only one store in town with game room) and play, they have pretty lax rules - don't disturb people at other tables and don't make mess ( also, no smoking and drinking).
In essence, when it comes to hobby in my neck of the woods, it's mostly fragmented into small home groups. And i don't particularly care what other people do in their home games.