At present, my current Greyhawk 5E campaign is at 17th level after 2.5 years of fortnightly play.
My previous Greyhawk 5E campaign reached 20th level.
The campaign before that was 10th level, and everyone was surprised when I ended it.
The campaign before that was 4E, and it reached 30th level.
A recent battle (taking an entire session) was this level 16 party against ten CR 7 foes. Ended up being very finely balanced, as they had to deal with the foes taking hidden passages and otherwise attacking from range. Most characters were badly damaged, at least one was unconscious at one point. CR7s challenging level 16 characters.
The fact is that it is entirely possible to run high-level D&D and have fun with it. A lot of the problem spells people talk about tend not to come up in real life that much. Occasionally you get "that player", and you need to adjust. (But, honestly, "that player" was probably causing you issues long before).
And then it's just being more flexible with adventures and their resolutions. Wizards has had a lot of trouble trusting DMs with its adventures - many of them are VERY scripted. It was interesting - when I first read Descent into Avernus, I read the last chapter very early on, and was really enthused by what it said. I expected there'd be a lot of freeform play before we reached the conclusion, where various deals would allow all the potential solutions to be possible. Of course, the adventure that actually appeared in the book was incredibly linear and didn't lead to those potential conclusions at all!
You can see more of "trust the DM" in the finale for Tyranny of Dragons, which I'm sure one reason some people don't react well to it. It's actually very bare. There's a tunnel complex, and a ritual chamber, and all these battles going on around - you can work out how to handle it. It's not that scripted, and a few more notes on how to run it would be welcome. But it gets out of the way of the players' mad plans and doesn't stop them from trying stuff.
There's a level of flexibility you need as a DM. More preparing situations into which the players can throw their special kind of chaos, rather than very structured "encounters". Of course, you could design a set of scenes - I do all the time - but with an underlying understanding of the situation so that when the high-level chaos ensues, you can react.
But there's also the question of how long groups have to play. I run my campaigns for typically about 3 years. (Some of my players have been with me for 25 years). It's not going to be that way for everyone. But are you then saying that D&D is only for people who can't play for more than 6 months?
I am curious about campaign story patterns, though. I rarely run "this campaign has one story" and do that, save when running a published adventure. I have several strands weave through the campaign's life. (My 10-level 5E campaign was an exception, where it was all about the liberation of Onnwal, and ended when they succeeded).
I must say I love seeing the players get to play with the high-level stuff.