Pretty much, but a lot of the content (servers, skins, etc) are player made. A lot of things can be purchased with their monetized currency.

Kids make content->Roblox sells in game currency->Currency is spent on content made by said kids

Edit: I guess this didn’t actually answer your question.

Players program and design games in like a server builder. People have made Call of Duty, mobile-ish clicker games, pirate battles, Starfield-esque servers. There are limitations but there’s been some pretty high quality servers made. Pretty sure they are almost all player made.