Don't limit this to SPAs, include the Jamstack, which has all the same problems, and the false promise that if you can statically render a few pages or parts of pages and put them on a CDN, everything will be fast. It won't, because to load dynamic content, you still have to do a lot of work and talk to a (gasp) centralized API over the internet.

SPAs and Jamstack favor developer convenience over end user experience. Let's have fewer loading spinners, and more SSR-by-default for pages with dynamic content.