They literally just said "unless the frontend is doing something profoundly stupid".

That's the norm in the React world nowadays. You should take a look at https://infrequently.org/2024/08/object-lesson/

This article is better, but has very little to do with React. The major issues I see are 1) loading a 2.5 MB AWS library (not React), 2) not doing SSR (not React) and 3) not tree shaking (not React). I agree these are all problems. But shouting to the skies about React is not going to solve them.

'React' is really just a stand-in for the excesses of client-rendered apps. Do you really think Alex Russell, after writing all these blog posts about the general problem, thinks that React specifically is to blame? Of course not. He is picking it as an example that often causes higher complexity.

I think his definition of profoundly stupid probably differs from other people's.