React has already jumped the shark, people just haven't realized it yet. The backlash will be big. I think most people will jump to Preact or Vue.
1. Awesome new tech,
2. Tech gets more and more popular,
3. Tech gets more and more features to better cope with new use cases,
4. People get sick of bloat and create awesome new tech to replace it,
5. Go to 1.
In 5 years time earnest conversations will be had about trying to find somebody who is willing to maintain the thing, or do we have resource for a complete rewrite?