The Node ecosystem is a mess and it starts with core being a hodgepodge of deprecated mush. I think it's more likely that wasm picks up steam.
Rails, PHP, Django, etc aren't going anywhere.
The former will keep going and keep solving problems, but it'll be relatively quiet in the grand scheme of things just like it is now. The JS ecosystem will continue to thrive in the latter world where there's more VC money, hype & RAM than common sense, so we'll keep hearing about it. As long as there's enough VC money to fuel the fire this situation will keep going (along with NPM's storage expenses growing alarmingly) but the second the VC money dries up and hype-driven startups die off, companies will mostly come back to the first approach and the majority of "React developers" will be out of a job.
The secret, or perhaps not-so-secret, is that the vast majority of web applications are still CRUD, and the average person doesn't understand the difference between a SPA and a server-rendered app. Most of the engineering effort that goes beyond that is probably a waste of time unless you really plan on doing things beyond CRUD. So the best thing is to actually understand the fundamentals, learn to do a good job at those, and use the tools that make sense for said job. That means that maybe, just maybe, your WebGL game doesn't need to use React.
But comparing Rails (a framework for complete web dev functionality) to entirely different paradigms and use cases seems kind of silly. These frameworks don’t solve everything, but they make it far easier and cheaper to develop a website with under, say, 500 million users. Once you get that large you can start exploring paying more devs for better efficiency.