I run two types of campaigns: beginner campaigns at school, and then my home games with friends and family, few of which are beginners, but also few of which care that much about learning Rame rules, so that generally falls on me.
My school games are short (under two hours), and there is an emphasis on keeping things moving so that everyone gets a chance. A few players are more experienced, and sometimes they use that to min/max and so on, but it's fine. I veto if the meta-gaming gets out of hand, such as when two players created artificers with the intent of using the "bag of holding trick" as a regular tactic. But issues like that seldom arise, and mostly my players seem very interested in building their characters' stories, which is great!
At home, almost no one cares about min/maxing at all and it's extremely collegial (with the occasional exception, such as a current new addition who will need to adjust to our style). I allow players to actively contribute details to world building while we play, and it's a very chill atmosphere. I might enjoy arguments on forums like this, as long as they remain rational, but in person I am pretty conflict adverse, meaning that I just don't bother getting into arguments for the most part, and it's the same in our group. I couldn't play in a group that had regular tension or that felt highly competitive.