It is
not important to keep your skill sets up to date, if by "up to date" you mean "having used everything that got a fair amount of press for a couple of months". You don't have time for that. Nobody does.
So don't chase press releases and puff articles. Chase real world results that fix your problems. If framework X fixes problems Y and Z, and you don't have problem Y or Z, then skip framework X. It's a waste of your time.
I'd say that once every 5 to 10 years, there's something worth moving on to even if it doesn't fix any of your current problems. The rest of the time, skip it unless you know why not.