even if svelte is better than react (which i'm not conceding yet), the tooling and resources around react are just unmatched. You'd loose so much velocity and/or capability by doing Svelte that you wont be running at all
This is a fair point to bring up and might be the main advantage of React at this point. But as a counterpoint to that, part of the reason that the ecosystem around React is so well-developed is that React itself (in its specific role as a sort of view layer) has like 80,000 libraries and design patterns for lots of necessary tasks like state management. And because React has been around so long, many of these resources and tutorials are out of date or otherwise questionable.
Whereas going into something like Svelte, you know that almost certainly you're going to use the built in stores and it's likely going to work perfectly for the overwhelming majority of common use cases. Does it really matter if the Svelte ecosystem is smaller and less developed if the right way to proceed in virtually any project is much clearer?
React is certainly "safer" in a sense, you're never going to get in trouble with your boss for choosing React, just about anything that you'll ever want to build with React has been proven as workable, you'll always have 18 dozen libraries to solve just about any problem, and you'll always be able to easily hire a pile of developers when needed.
I don't know if there's an objective right answer because every situation is unique and we're sort of dealing with an opinion, but I know which way would increase (this) developer's happiness level.