But let's not be kidding ourselves: When we think of the best TNG had to offer, it's comprised of maybe 20% of all episodes / scenes. At best. The rest suffers (sometimes greatly!) in quality due to, among others, cringy dialogue; even for the time tone deaf handling of certain societal topics; derivative stories; predictable, repetitive plots; one dimensional characters with only few exceptions; uninspired and very tame sci-fi concepts...
Everyone's mileage may vary, of course, but I thought this snippet worth pushing back on. On several levels. First, I think your 20/80 categorization is too simplistc. Second, for me, I'd say you have your values reversed.
I kind of look at thing in tiers. By your reckoning 20% of a 26/22/24 episode season yields 4-5 classics (Trek at it's best) per season. I think, on average, that is in the ballpark. Though I must say, some of the best Trek seasons (TOS1, TNG 3-5, DS9 4-6, VOY4, ENT4) are gonna come in significantly over, while some others will come in under.
But my bigger issue is with the other 80%. For me, while I'll admit there are cringeworthy moments from time to time, and some clunker episodes (Tom & Harry in the holodeck, again), I enjoy the non-classic episodes just fine. "Sub Rosa", "The Outrageous Okona", and "Code of Honor" bother me not one iota (though great episodes they are not, well below average). And I enjoy most average episodes a lot.
Largely, I try to view the series as pieces from the time in which they were created. So some of the TOS stuff I write off as those were the days. Berman era gets less of a pass because it is more recent (35 to less than 20 years). Now, does it bother me that they always managed to stick the hot girl in a non-standard uni (Troi, Kes, Neris, Seven, T'Paul) while simultaneously claiming to represent a future of equality & progress? Yes, yes it did. But then again, Kirk's shirt seems to come off a lot. And sexy has always been a part of sci-fi. For better or worse. Though Seven & T'Paul were particularly egregious.
And Trek did make some progress. All the women were in short skirts in TOS. Just Troi in TNG out of uniform, and that got fixed eventually. Men in skorts in some scenes. At least all of Starfleet was standard by DS9. And T'Paul got out of her suit eventually.
Again, I tend to look at things that are dated on the shows as a testament to the progress we have made since 1966 (or 1987). And there has been a lot. Imperiled as much of it may be.
The tech advances are in one category. Floppy discs on a starship (or laptops) is no longer futuristic. So it does not bother me there ate now 3D printers & such on the Enterprise. The continuity has to give way there. But it is reflective of the tech progress, and is, in a way, reassuring.
And so are, to me at least, the dated social stuff. Girls can wear pants now. And be Captains. As can blacks. And even black women! LGBTQ folks are real and actually appear on the show as real people with real relationships. That isn't being overly woke in the new shows, it just reflects the progress we have made on those issues. It ain't woke, it's real. (Plus, Trek has always been woke, but that is another issue).
On the flip side, when I watch an episode from 1966 or 1987 and it is out of step with where we are now, I don't hold it against the show. I still enjoy it. And it, too, is a sign of progress I find reassuring. I don't cringe, or at least, not for that type of stuff.
Again, YMMV, which is fine. And I realize your critique was obviously broader than the social stuff. But I don't find 80% of Berman era Trek boring. And I thought there was a higher percentage of cringe in DISCO/PIC than any other Trek (save maybe early ENT).