Other than the lack of respect and career ceiling, the worst thing about frontend is how quickly things change and knowledge is considered out of date, so there's very little stability.
Also frontend is in a weird stop right now where enterprise frontends have stabilized on React, redux-toolkit, and likely some styled-components like CSS library - but personally I much prefer Zustand for state management and Tailwind (which to a traditionalist will look like sacrilege at first glance). In this last interview I was rejected from I was given redux coding challenges, which I completed, but since I stopped using redux many years ago maybe I wasn't as fast as they were expecting. I guess what I'm saying is in the past it was enough to have worked with any UI library like React, Angular, VueJS, etc. and be generally sharp, but now things have stabilized such that it seems that companies seem super picky in wanting their specific slightly outdated enterprise-y tech stack. Which I mean if that's your standard, fine, but they don't at all seem knowledgeable or interested in discussing alternatives (in total contrast to when I interview in which it's what I'm way more interested in discussing in an interview than some lame coding exercise that says practically nothing about the candidate).
You're prob right on the outsourcing, and that's even more signal to gtfo of frontend as that just signals increased competition, lower compensation, and is a reflection of frontend's second-tier status.
I love full-stack. I just keep interviewing at companies that say they're hiring for both backend and frontend, but regardless of what I say I'm interested in they shove me down their frontend pipeline.