For American shows, it's often credited as the first, but I don't if it actuall is.
British shows like Blake's 7 did it in the 70s. And Soaps I guess too.
The show was kind of a pioneer with using not just CGI for TV, but also using virtual sets. Definitely primitive by todays standards though. To bad they cocked up the VFX When they "remastered" the show from the original 4:3 to 16:9. The show was actually originally filmed in 16:9, the show and it's effects were produced in 4:3. When they made widescreen versions for the modern era, all the shots with effects were not only cropped, by badly processed, so they literally look extra shit then they originally did. Though scenes with no effects are true widescreen.
To get back on topic. Commitment is a downside of arc shows. And I kind of despise the fact neary all shows seem to be that way now. I like my episodic stuff.
And Babylon 5's pacing was actually done pretty well. Specifically the build up.
Season 1 was mainly episodic with maybe 6 out of 22 eps dealing with the main arc.
Season 2 had a few more eps dealing with the main arc.
Then Seasons 3 went full arc, but at a good pace.
Season 4 was still a full arc, but at a bit of a faster pace. Because the creater didn't know if the series would be renewed for a 5th and final season, they crammed about 1 and a half seasons worth of story into one season.
The final season then had the rest of the main arc story, with a filler mini arc added.
And I guess I was replying to Celedam's post on B5. But noted.