I honestly don't feel like Svelte makes things simpler. And I'm saying this as a "fan" of Svelte and think its compiler is very cool.
It just feels a bit weird that there's special .svelte specific rules.
Runes kinda fix this, but it's still a bit weird.
I think Solid or Vue are much simpler (but only did small projects in them) and have a simpler mental model. I've not yet used Preact, but heard good things about it