I see this as a common sentiment, but I don't see it IRL.

SPAs aren't a fad anymore; instead, they're the norm.

Web development over the past 3 years has majorly stabilised compared to the last 10 as a whole.

Want to work on the frontend? React. It's everywhere and can't be considered 'just a fad' in 2021.

Backend? Wrap your head around REST and you'll be fine with most languages (C# with .net core is very common, although often underpaid in my experience).