Chaosmancer
Legend
Yes, it's called bloat. In this case whereas before rules from Tasha's were optional, now they are part of the base game, and the base game is growing bigger and more complex. Each new piece adds to the DM's stack of things to worry about, and hence to their cognitive load.
But for those of us who were using those optional rules... there is no or little change. Now, clearly WoTC can't tell who is using what, but the assertion is that WoTC is making the game worse for DMs (and some people are asserting that WoTC doesn't care or flatly hates DMs). But if you are a DM who has been using this material.. that is frankly not true. We've gotten martials adding status effects. That's it. And it is barely more to consider than if WotC had made some new subclasses and you were running all of them in the same party.
Teaching also adds to the DM's stack. Now they are not just playing a game with players but have to treat those players like students. And like students, some players will 'get it' right away, whereas I've seen other players struggle with knowing what bonuses to add to their attack even after years of playing.
Now, some groups certainly want more combat complexity in their game, and can handle it. Hence the popularity of PF2 or Level Up. But a lot of people prefer a simpler game; the reason I now prefer to run OSR games when I'm GM is not so much that they are deadly, though they are, but because they are rules lite. It makes them easier to teach and easier to run, IME.
Okay, if you as the DM don't want to teach a new player what prone means, then have a veteran player do it. If none of your player's know what prone is... then yeah, you are the only person who can teach them. Sorry. That's the additional challenge for running for newbie players who don't know anything.
But, even then, you likely have someone who does know the game well enough and can help the players keep track of things, to lighten your load. Really, if you are a player at the table, you should be helping your DM. It is just common courtesy.