It really has.
And I don't mean Game of Thrones or special Netflix series…

I've just been catching up on the first series of Andromeda, which was a reasonably decent and fun SciFi series from 2000, from the mind of Gene Rodenbery of Star Trek fame.

The thing is that made me realise that it's almost 20 years since it was made and it STILL looks great today, the stories flow, it's fun.
But it also made me realise that when I was first getting into Star Trek in the early 80s THAT was less that 20 years after that show was made and even back then it looked a bit cheesy and low rent, with dated plots and ideas.

The same with Lost in Space, Land of the Giants, Voyage to the Bottom of the Sea- I started getting into those just a bit less than 20 years after they were made and they all felt quite dated, but stuff that's over 20 or even 30 years old today like Farscape, the later Star Trek series and stuff DON'T Feel as dated or look as shit as those 1960s TV shows did to me back in in 1980s. (or late 70s or whenever I started watching).

There is a massive amount of high quality, amazing scifi (and everything else) around now for people to get into, decades of it!
Everyone is really quite spoiled. Back in the old days we didn't have much choice at all.

That said, there were some non-US alternatives like Dr Who, Blake 7, Space 1999 etc that were darker and a lot more interesting and experimental than those famous US network TV SciFi faves. And while the image quality, props and effects might not hold up all that well now, the stories and acting and plots do.

I don't mean to knock the original Star Trek, it really WAS pretty fantastic, but there is a lot of stuff in it that dates it badly, a lot more than other things.

Yeah TOS was a very 60s show in many ways and that aesthetic dates it more than Andromeda which despite some early 2000s stylings it does hold up visually quite well. The acting was never good to begin with but there writing was always solid enough. I think it helps it came when it did though, 10 years earlier and it would look much more dated, and no I don't mean 10 years more dated. Filming quality for TV shows improved and ratio aspect adjusted for widescreen Tvs. Look at the star trek ds9 and voyager they weren't much earlier but look like there's more of a gap.

That said TV has come along way since then, but it's more in the over arching story elements and more cinematic direction employed. There isn't as shows that do the event of the week style story telling anymore, for better or worse.

Actually, the first TV show I thought looked good - really good, like cinema-level good - was Mad Men. And the first anime series which looked consistently good was Ghost in the Shell: Stand Alone Complex. (Not that there weren't good looking episodes here and there, but not a single consistently good-looking show.)
Obviously, look and quality are different things, and there were great shows. Twin Peaks certainly had a great style, and some X-Files or Millennium stuff was appropriately moody. But as far as I am concerned, TV never looked really that good until, say, fifteen years ago.

Technical skills and production quality has come a long way in 50 years.

But compare a Sean Connery Bond film to a Daniel Craig one. Different cameras, require different direction of photography and set dressing, make up and so much else.

They use movie equipment now, movie budgets and HD. Hi-def can be very unforgiving.

It's really brought TV and movie camera work to the standards Natalie Kalmus enforced on early technicolor films.

Speaking of ST:TOS there were a couple of later episodes from DS9 and ST:Enterprise that revisited the original ship with modern techniques and it was a whole different aesthetic. Sisko or was it O'Brien called it clean 23rd Century design.

There's a good fan series Star Trek continues that captures the whole look as well. It can be approached as a different design aesthetic as opposed to primitive TV production and it can work for a modern series. TOS had some unique lighting to further its clean futuristic look.