Or at the very least, stopped the momentum of a fad, or signaled the end of an entire movement. The movie industry has numerous (https://tvtropes.org/pmwiki/pmwiki.php/GenreKiller/Film) examples (https://www.reddit.com/r/movies/comments/p1yeiv/what_are_some_films_that_killed_genres_stopped/) of this but I haven't seen as much for television (https://tvtropes.org/pmwiki/pmwiki.php/GenreKiller/LiveActionTV). For example, Pink Lady & Jeff is often cited (https://sites.google.com/site/cultoddities/home/sid-and-marty-krofft/pink-lady-and-jeff) as the show that once and for all, destroyed (https://45ruminationspermegabyte.com/2017/05/17/why-tv-variety-shows-died-pink-lady-kiss-in-the-dark-1979/) the viability of the prime-time network variety show (https://www.quora.com/What-led-to-the-demise-of-variety-shows-on-television-There-were-dozens-in-the-60s-and-70s-and-then-poof-the-concept-disappeared).

Wasn't the 1969 Blondie sort of an end to the post-Batman "camp/comics" era?

Jimmie Walker has at the very least, insinuated that his show, Good Times (https://web.archive.org/web/20061031125158/http://www.jumptheshark.com/g/goodtimes.htm) killed off in his words "minority comedy" due to all of the controversy and complaints that it created and generated when it was on the air:
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He went a step further by saying that a show like Good Times (https://www.datalounge.com/thread/15692577-the-decline-and-fall-of-good-times) would never make it on the air beyond the time that it was originally on. He also said (https://www.lipstickalley.com/threads/jimmie-walker-of-good-times-youll-never-see-a-poor-black-family-on-tv-again.1200370/) point blank that, you'll never again see a poor, struggling black family like the Evans family on Good Times (https://web.archive.org/web/20140330010016/http://forums.televisionwithoutpity.com/topic/3078132-good-times-aint-we-lucky-we-got-em/?view=getnewpost) or a JJ (https://goodtimes.fandom.com/wiki/J.J._Evans)-like character (i.e. a wacky, comic relief character who just so happens to be a minority) due to concerns that it's projecting negative stereotypes. Basically in Jimmie's words, minority shows now have to essentially be like The Cosby Show (https://web.archive.org/web/20140330010016/http://forums.televisionwithoutpity.com/topic/2603773-the-cosby-show/?view=getnewpost), in one way or another.

From the late 1940's to mid 1970's, variety shows (with musical numbers and comedic sketches,etc.) once were a staple of television but the last truly successful one was 'Carol Burnett' (1967-1978).
There were a few sporadic attempts to revive the genre but none lasted. Perhaps the most infamous one was 'Pink Lady and Jeff' (1980) which had this flash-in-the-pan Japanese girl singing duo (who had a song actually chart in the US) who barely spoke any English team up with the obscure comedian Jeff Altman. They'd sing their tunes and politely giggle at his gags and had guests. That's about it. Although they had the once-renowned TV star Sid Caesar guest as their samurai father making life hostile for their Western dates.
Not surprisingly it got cancelled in six weeks and there were few if any attempts at variety shows.

According to "13 Week Theatre" (https://www.youtube.com/watch?v=rJImpUGZsNY), My Mother the Car may have simultaneously been the peak and nadir of high-concept sitcoms.

It along with I Dream of Jeannie, which also premiered in the fall of 1965, proved to be the last of the supposedly great fantasy based sitcoms from the golden age of television. This included Mr. Ed, The Patty Duke Show, Bewitched, The Addams Family.

For the next few decades, sitcoms while still being highly conceptual were otherwise, firmly rooted in the real world.

>>...My Mother the Car may have simultaneously been the peak and nadir of high-concept sitcoms. It along with I Dream of Jeannie, which also premiered in the fall of 1965, proved to be the last of the supposedly great fantasy based sitcoms from the golden age of television....<<

Not quite over then -- post 1965, fantasies kept coming into the early 70s. What about It's About Time, The Flying Nun, The Ghost and Mrs. Muir, Nanny and the Professor, Get Smart, and Mr. Terrific (-- and of note, though not sitcoms, Batman and Dark Shadows)?

(...and arguably... the high-concept Green Acres, The Monkees, My World and Welcome to It, The Ugliest Girl in Town, The Pruitts of Southhampton, Blondie, and When Things Were Rotten, all unreal or surreal if not outright fantasy. The Girl With Something Extra tried to have it both ways but seemed to abandon the ESP premise after the pilot in pursuit of faux-realism).

Pink Lady and Jeff was very cringey to watch.