@jan i ve started with raw js grml and css, after that i ve worked with react but after some months i eanted to learn svelte because it was more familiar with the js in html vs html in js (react s approach), and the web perf is much higher with a svelte app because of the bundle size in the most part. For example i ve used sveltekit on my saas
https://naav.ro, i have server side and client side combined without any headache, if you want you could try Solidjs which haves the same approach with react but the perf is much higher. My advice is to try svelte with sveltekit because the dev exp is much better.