I have been hearing warnings for a while now that distributed services and JavaScript running in the browser are about to reach the point where no one will want to work on Drupal any more. That would be true if no one cared about vendor independence and future-proof investment. If you’re building a disposable site or afraid that your client will run out of work for you, it may not pay to worry about those things. But if you would rather not do the same job over and over again, you want a platform under your own control that can be continuously reused and improved upon.
The mentality of the Drupal community has moved from “not invented here” to “proudly found elsewhere.” We reuse technology from other open source projects when possible instead of developing our own. When JavaScript technologies are the best solution, we can build Drupal with them. Some of us are already working on using React to improve the performance of the admin interface. As long as there are people who care about vendor independence and future-proof investment, Drupal will continue to improve.