I believe it because it seems to be the consensus I gather whenever I read articles about theoretical physics' hunt for the unified theory. I'm talking about that problem specifically. The search for the unified theory sounds basically dead, and we have a generation of physicists who have spent their careers going down dead ends. The meme seems to be for the field to move past it and focus on more "productive" areas of physics that can have practical use.
I can only gather this from 2nd hand accounts in pop-sci articles and mainstream physics books, but the lack of falsifiability and experimentalism for these things, combined with a large surface area of failed attempts, seems to have left physics in a rut.
Sure, theoretical high-energy physics (i.e. particle physics) seems to be in somewhat of a dead end when it comes to finding a theory of everything. But this is an incredibly small part of theoretical physics.
I can only gather this from 2nd hand accounts in pop-sci articles and mainstream physics books, but the lack of falsifiability and experimentalism for these things, combined with a large surface area of failed attempts, seems to have left physics in a rut.