Honestly I think a lot of what you're noticing is the product of junior frontend devs. The nice thing about HTML is that it's really hard to write code that won

Honestly I think a lot of what you're noticing is the product of junior frontend devs. The nice thing about HTML is that it's really hard to write code that won't load fast, but you can write SPA which load fast, you just need to be more deliberate about how you load things and what you're loading. The problem with SPAs it's easy to create huge bundles pulling in numerous large packages then loading it all in the head where it will block page render. Layer that with some poorly designed APIs and slow JS animations and you have what you're describing. I'm not saying SPAs should always be used because in most cases they shouldn't, but a well optimised SPA should in theory be quicker and provide UX improvements to the user.