Put simply, Svelte and React were at two ends of a spectrum. React gives you almost complete control over every aspect of the lifecycle, but you have to be explicit about most of the behavior you are seeking to achieve. Building an app with React feels about 80% on the JS and 20% on the HTML side.

Svelte on the other hand felt like a breeze. Most of my app is actually plain simple HTML, and I am able to sprinkle as little JS as I need to achieve my desired behaviors. Sure, Svelte <=4 has undefined behaviors, or maybe even too many magic capabilities. But that was part of the package, and it was an option for those of us who preferred this end of the trade-off.

Svelte 5 intends to give that precise level of control and is trying to compete with React on its turf (the other end of that spectrum), introducing a lot of non-standard syntax along the way.

It's neither rigorous Javascript like React where you can benefit from all the standard tooling developed over the years, including stuff that wasn't designed for React in particular, nor a lightweight frontend framework, which was the initial niche that Svelte happily occupied, which I find sadly quite empty now (htmx and alpinejs are elegant conceptually but too limiting in practice _for my taste_).

For me it's a strange "worst of both worlds" kind of situation that is simply not worth it. Quite heartbreaking to be honest.