We've had so many generations of Web frameworks, but presumably it's still not a solved problem, because we keep moving to new ones.
Of course, sometimes the latest thing has a useful mix of properties that is worth the move. Though many hottest ones turn out to be popular only for a year or so, and then people lose interest.
I wonder how much a factor in the churn is the individual engineer desire to have the newest framework keywords on our resume, even when we can tell it's mostly a gratuitous rehash, because a lot of hiring is for keywords.
Or maybe more often we're looking for the new tools to provide additional advantage for projects (not resumes), but it's difficult to assess the holistic net payout until we've invested heavily in it for a year, whereupon we repeat with the next tools that seem to promise advantage.
I'm all about trying new tools all the time, especially as little side/toy projects, but it's odd that we are often betting important projects on less-proven new tools, when you'd think by now we'd have figured out and proven tools that would be hard to beat. (And I say this as a fan of certain tools that aren't proven enough, but which I wish a few startups would use for getting to demo/launch, so I can humbly see one way this happens.)