Well, I don't. I try to focus on basics and rest I learn on the job.
To be honest I know that I have less value on the market because of that. It is just I don't want second job of just keeping up.
I read article here and there when I have moment, but that's about it.
On other hand I find ecosystem in JS (my slice of cake) is slowing down. There is no new framework every week like it used to be. No ground braking changes.
I also don't very frequently, but not just because it's not interesting most of the time. It's because as you learn enough of them, the same realization happens; most of what they do, aren't as important as you just building the thing quickly in your stack of choice. Truly new tech and categorically different tech is different, but a new JS framework or w/e doesn't really matter much at all.
Consequently, it's becoming painfully aware to me that if I were to lose my amazingly well-paid job in which I (feel like I truly) excel, it'd be a pain to look for a new one. Because of my niche, I would, most likely, have to go down with my pay by one or even two seniority levels to be a standard SWE in a different company right now.