There’s lots of people able to work anywhere on the stack but choose to work on the frontend because they feel super-productive compared to others. They can switch between frameworks and even come up with new ideas.
On the other side, there’s way too many frontend engineers that can barely write tests, have extremely little ability with the visual part, have never setup a new project, but are still getting super small things done.
Given that the frontend is the first thing users interact with, doesn’t that make it one of the most critical parts of the entire product experience?
My pet theory is that innovation happens when you look at https://xkcd.com/1205/ and estimates it's not worth it and do it anyway.
Computers have become faster while websites have become slower. You can go on a random webpage and usually see 100s of MBs of memory being used while we had computers in the 90s running 3D games with around 1/100 of that. LLMs have partly become popular because people don't want to enter the current wasteland of web pages who couldn't care less what framework you used and just want to get what they are looking for and to get out.
You will see people write things like "powered by React" as if React is doing any thing except running more JS. You are not getting any closer to the CPU or any of your hardware that actually runs your machine.
At best some of these front-end devs want to appear as if their job is far more complicated and sophisticated than it is.