This is something I really struggle to understand about the modern web dev mentality. What is exactly so bad about reloading a page? You get visual cues that the browser is doing work, and the page you requested is being downloaded. On the other hand, some SPAs literally provide zero cue when a route has been changed, which is just awful UX to me.

Agreed. For the most part I don't really care, the target audience of those services is probably people who put up with that kind of bullshit. But there are cases when functionality and compatibility should trump everything e.g. banking software or e-governance.