The fuse is now lit for lots of apps currently working fine in production to be suddenly labelled 'legacy', and nobody wants to work on the crusty old React or (heavens to Betsy!) Angular anymore.
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?
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.