Well, we're currently playing "feats only". I like feats, but I think next game, I'm going to play without them. As for multi-classing, we decided after a long look to get rid of them, and only one player is put-off by this decision... and he still absolutely understands why I made it.
I'd be all for getting rid of feats if I had a player seriously interested in sharp shooter or great weapon master. Strangely, no one is, and so they work quite nicely. But yeah, I'd prefer to get rid of the added complexity, and just have everyone make simpler characters.
Although I respect your opinion, I confess that I don't understand it.
Different people like different things. Some like feats, some don't. Some like multi-classing, some don't.
But I wouldn't dream of saying, "I don't like multi-classing, therefore no-one else at my table is allowed to multi-class!"
I don't like playing wizards, but I wouldn't ban other people from playing them!
If you don't like multi-classing (or feats) but another player does, how does it spoil your day if they make use of that option and you don't?
I know I'm replying to your post, but my reply is to anyone who bans either option.
I've played two 5E characters so far (although I've been playing D&D since the seventies); the first is a single class variant human, but every time I level up I'd rather take the next fighter level than 1st level in a new class. I'm happy.
The other character was designed as a multi-class concept from the word go. I wanted a conflicted character, and chose a paladin/warlock. Briefly, he thought his god Wotan had sent him one of his two ravens (Hugin) that fly over the world during the day and report back to him at night. My PC believes that Wotan has sent Hugin to help him. What my PC doesn't know (but I do) is that his prayers are not heard by Wotan (who may or may not exist!) and are instead answered by an Archdevil
pretending to be Wotan, and has sent a shapechanged Imp to very gradually corrupt him over the years.
So, he started with two levels of paladin and now has three levels of devil-pact warlock and just gained his Imp familiar (who stays in raven form).
This PC is good at some things and not so good at others. For example, he wears plate armour and uses a greatsword (when a min-maxed warlock would spam
eldritch blast and/or have blade pact), but he only gets one attack when all the other warrior-types get two. But although I'm aware of this objectively,
subjectively my PC feels awesome! Isn't that the most important thing in an RPG: that
you thing that your own character is cool? If you didn't, why would you play?
I'm not convinced that banning multi-classing has any benefit whatsoever. It may not be the way to introduce a new player to the game, but that's not a factor for long. I certainly couldn't have made my latest PC concept work if multi-classing were banned.