I'd love to hear more about what motivated the switch. All the additions to react-router are, afaict, opt-in. React-router has 3 "modes"[0] and the declarative mode seems pretty much exactly what the classic library is like with some extra components/features you don't have to use
Thought I've enjoyed the code-splitting and access to SPA/SSR/SSG/etc strategies that come with the "framework" mode