One thing I notice is that even though "old school" D&D supposedly puts the DM in a much more authoritative position, I remember much more time spent arguing rules in the 80s. After a long break, coming back to the game with 5e, it feels like the DM has much more authority. For all the talk about collaboration and complaints I keep reading about overly entitled players, 5e seems to be played much less as game with rules than AD&D. Yes, it is partly because OD&D required you to fill in large gaps and AD&D rules were difficult to parse. But there was more of sense of game masters being referees and judges. "Rules lawyers" became a pejorative early on, but almost everyone I played with in 80s were rules lawyers to some extent. Challenging the DM on ruling now seems to be the height of poor gaming etiquette, which is a bit weird for a game when you think about it.
You wouldn't know that looking at D&D discussion threads, but in every game I've played at, whether convention games, AL games at my FLGS, or on-line games, since 2014, I can't recall a single instance of any debate over rules. It feels like a big cultural shift to me having jumped from the 80s to 2010s. I note this without any judgment either way. I enjoy both styles, though I tend to a bit more on the gamest side when I run D&D games, especially combat and am not only tolerant of some debate over the rules, I tend to rely a lot on my players to remind me of less-used rules and help adjudicate results.
Wondering whether others have the same experiences.
I've always just shut down arguments quickly during the game. I'll listen and on rare occasions look something up, but most of the time I'll simply make a ruling and we move on. If the player argues, I'll just let them know I've made a ruling and that we can discuss it after the game if they want. In my experience it's pretty common. It's not DM as dictator, it's DM as the person who keeps the game moving.
I think 5E emphasizes that approach - DM rulings over rules. It helps that the rules are relatively clear in most cases and there's less contradictory advice. But I think it also helps that they've accepted that the rules can never cover every possibility. That you don't need detailed rules for a lot of stuff because they just tend to bog down the game and different groups will want to tailor the game to their preferences anyway.
When it comes to rules lawyers, I saw them more in previous editions, then again the games I've been involved with use DndBeyond so it's pretty easy to look up a rule for a PC. It feels like there are fewer true exploits than previous editions, with a lot of the power creep stopped by simply disallowing optional rules. It helps that feats and multiclassing are optional.
So it's not that I don't occasionally see questions now and then (or raise them myself) it's more that the DM makes a call and says "That's the way I rule" and we move on.