Remix has one of the best stars/issue ratios I've ever seen in a large project. They have 27k stars for 228 issues (118 stars/issue). Meanwhile next.js has 121k stars for 2678 issues (45 stars/issue).
Remix also has a robust future flag system to ensure nothing breaks during transitions. https://github.com/remix-run/remix/issues/4598
For larger changes (like the controversial flat routes), they even maintain the old feature so you don't have to upgrade. https://www.npmjs.com/package/@remix-run/v1-route-convention
I don't think the evidence supports your assertion.