That's a GUY in your avatar?!

Yes, that's a guy. You don't know
The Cure?! Where were you in the eighties?
Hopefully, a better place.
All things get old and forgotten to some extent.
In general, yes. But how old and forgotten varies. We're still influenced by works which are rather old - the Bible and Shakespeare remain two of the best selling commodities in the English language, and neither are particularly fresh.
In the sense that most people my age haven't seen or care to see old movies like Robert Wise's 1945 film The Body Snatcher, which is very hard to find on DVD (sometimes it shows up on eBay).
That's a fair point. I'd never heard of the film until you mentioned it and did a quick google. You're right, it's unavailable. But many even older films are widely available on DVD, going all the way back to the infancy of the silent period.
I watched the 1948 adaptation of Hamlet the other day with Laurence Olivier. I'm willing to bet there are six or seven people my age in the world that I can talk to about that film.
Seen it, own the DVD. I think it's got a lot of clever, concise editing to trim down the play to a shorter film length, but I don't think Olivier makes a particularly good Hamlet. There's not a lot of emotion or intensity in his monologues, he delivers them very stoically. Now, I like Olivier, but the best film performances I've seen from him tend to be films like
Rebecca, where he isn't straitjacketed by Shakespeare, but that's another story...
TOS is gaining modest popularity again, but so many will watch one or two really bad episodes, roll their eyes and tell the world how cheesy, campy and not at all serious the original Star Trek, trying to warn others. Another will simply be put off by old footage and old production values. I honestly think this will be the first and only time TOS will get a face-lift special effects wise. I'm sure it will stick around in some format or another in future decades with limited Criterion Collection releases where you have to go to Barnes & Noble to buy it physically and some really old critics and pundits will still claim it is a classic.
What's so limited about Criterion Collection releases? They're pretty easy to get and are almost invariably top-notch. But I agree that I don't think the improved special effects will make the show more accessible. If you were going to be put off by 60s SFX, you're going to be put off by 60s fashion sense and the cheesier hours of the program. I don't know if TOS is gaining popularity again but I'm likely to be oblivious to any such pop culture trends. It's about as known now I think as it was a decade ago.