I have used both SvelteKit and React. Dev velocity was great in the beginning with SvelteKit when everything was super simple but decreased drastically as the project grew. Went back to Next. Apart from devs, none really cares if you wrote it in Svelte, React or bare HTML/CSS or if your site loads double digit milliseconds slower.
My app had about 50 routes (by the design there were about 80 pages, but of course some common patterns emerged). I wouldn't call it large, but it's past "toy" and probably not "small" for most.
I didn't have a problem, so I'm curious what the previous poster ran in to.
the only thing I can think of is that it doesn't impose much structure on the "lib" folder -- that's where code/components that aren't directly in the route files go. But there's nothing keeping you from keeping that organized yourself. So that's not really a problem, but something you might want to think about early if you plan to build out the app in the future.
I have tried to use sveltekit once and turned around in 20 minutes as routing is severely limited. All I wanted to do was to route based on domain, with a different set of routes for one of the domains. Not exactly complicated or uncommon, but not something you can do with the sveltekit router.
This is gone over in the github threads about such a feature - basically, as two different projects semantically, the best thing is to create two different projects physically, in a monorepo. All the code-sharing with none of the additional complexity.
As for routing, I guess that gets unmanageable pretty fast. Just in the sample blog tutorial here [0], you get confused with the number of files and nested folders that has same file names as level above.
