This is the broad consensus among everyone else I know using Next - they felt like the Next 13 release and the app router was a rug pull from a previously pleasant experience.
And whenever you complain about this or ask for support, some devrel guy from Vercel shows up in your replies, saying something to the effect of "Wow! That's crazy, we worked really hard on Next 13! This is my first time hearing about this!"
Edit: Since I know the devrel guys are in this thread: If you want people to keep using Next, something fundamental about how you guys write the framework needs to change. The instability and lack of documentation makes developing with your framework a massive pain in the ass - anyone I know who can is migrating off it as quickly as possible.
There might be a point where app router is stable & smooth but it's pretty clearly not right now, so havn't really seen the need to upgrade. I think there was a pretty decent comms issue with the stability of it from both the Next and React teams, but I have a hard time faulting an otherwise fairly stable and useful framework for adding features when they're not breaking the existing stable path.
Hooks was a bit of a bumpy transition as well, but I do think that I prefer the code written with them to the code before them. I think it's OK to wait a year or two to let the rough edges get filed down when these types of frameworks release big new feature sets.
Edit: I'll note that we don't use next/image or API routes either, both of which I've seen some churn / pain with. Possible I just hit on the framework when it was in a pretty happy place and most of the new features or suggested defaults have had pain points that I havn't experienced.
The moment people realize that this tool allows you to enhance the volume and quality of your work output with little effort, whether it is authentic or not, it's use will catch on like wildfire.
Arguably it already has with students and knowledge workers, even outside tech centers. Schools and universities everywhere are suddenly contending with how to evaluate students in light of the availability of LLMs.
Why is it catching on? In the best light because it actually is a tremendous productivity accelerator. In the worst light, because we live in a world that incentivizes "fake it til you make it".
It's great at a few things and pretty good at a lot of things. In my view, the thing that it's the absolute best at is churning out low value, rarely-read communication. There is a massive amount of that type of communication - spam, student essays, procedural documents for compliance. There are loads of jobs that need to do that sort of thing regularly and it's a godsend for them.