The standard answer to that is that some technologies make one harder than the other. That's kind of true from first principles, but it requires making the case that e.g. React is actually harder to make good than a plain HTML page.

Fun thing, TFA describes a kind of multi-page wizard style form that I haven't seen a lot anymore in the last decade or so. But when I did see it, it's always some dogshit enterprise system. Some Oracle product for expensing expenses last time.

The problem with those things always seems to be that they are slow in the middle of doing your task. Every button is seconds of waiting. Doubly annoying if you have to go back a step or two. The badly coded SPAs seem to be slow at the start. It takes a while to load, but once it's loaded its performance is usually okay.