I've spent plenty of time optimizing performance. It almost always comes down to a backend issue, unless the frontend is doing something profoundly stupid, like making multiple API requests in serial when they could be batched or parallelized.
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.
