I've been running Svelte with esbuild and it's incredible, and doesn't bring along all of the above overhead. I get to target modern browser stacks which is a huge plus that keeps a large amount of complexity out of my toolchain.
Mileage will vary =)
I rather like Svelte.
But honesty requires that we recognize that Svelte also uses Webpack/Rollup + TS + Svelte etc etc.
I like the idea of Snowpack. But if A.svelte and B.svelte both use C.svelte, Snowpack has to do a lot of redundant work to provide A.js and B.js with Svelte.js and C.js all converted again and again from ts then baked into both A.js and B.js. That's a lot of server work and a lot of client work and a lot of network work.
So you still want a webpack or rollup or what have you to bundle and tree-shake and codesplit for production. I don't know why this irritates me more than running any of my other code through a compiler. But it always has.