i just want to be a software engineer without having to continually burn away evenings and weekends studying the latest shiny, continually for the next two decades, just to keep my career afloat. is that even an option anymore?
Don't read too much hacker news, it kind of becomes stressful and I would try enjoy your weekends, don't worry too much about the market, a lot of good people just burn out and have breakdowns by trying to understand all that's going on and become useless anyway. Just know the basics well and learn what you need to in work hours, make time.
What I'm finding is that in the end, most of the good / important stuff ends up condensed into a nice O'Reilly (or similar) volume that you can read at you leisure' later on when the hype has evaporated. If you invest yourself too much in the latest tech constantly, you run the risk of it being redundant / replaced anyway.
If you are okay with median compensation and median project importance (internally and externally), then sure, wait a couple years when the interest has died down.