And the funny thing is that it's complicated to even block all their spam in Gmail, because they send it from a bunch of different email adresses

Of course that is a valid way to play, but as a player i would miss the sense of exploration that a pre-created world offers. I also find it more immersive if the GM comes up with the world and i just interact with that. I usually dislike when GMs hand creative control to me to come up with some aspect of the world on spot, it takes me right out of my character's headspace. I also like sitting for hours coming up with ideas as a GM, although i agree that would be way too much prep. But there is no wrong way to play as long as everyone is having fun, it's all just preferences. I'm just writing this to show that there are people who like GM-authoritative games better.