I’m remembering this specifically from a UK point of view, but definitely was the case for US TV also.
In the 90s I used to watch The X Files, Strange But True?, Fortean TV, Eerie Indiana… GhostWatch was a one-off that unfortunately I missed at the time.
There might be a couple of other shows I’m forgetting…
But looking back it seems cool to me that mainstream TV was so into “weird” stuff back then.
IMO, this is largely due to TV shows have moved away from episodic, monster-of-the-week style, shows. Like Buffy, etc. The best we have recently are anthology style like Black Mirror. Honestly, I’d love it if Stranger Things made it monster-of-the-week rather than a whole season story arc.
Even Buffy eventually moved away from the MOTW format, and after a while I got sick of the ongoing convoluted arcs and lost interest in it. (I still need to watch the musical episode though…)