The "jump the shark" moment with The Brady Bunch for me was when Mike's boss sent him to Hawaii on a business trip to "check on a building he designed" or whatnot and invited him to take the entire family on company expense, including the maid, Alice! They ended up being on the island for several weeks (to check on a building) which took up much of the fourth season.
I mean, c'mon. Even as a young child, I knew that it simply wasn't feasible for a man, working as a mere architect, to take his entire family and a maid on a multi-week business trip to paradise and then be allowed to put it all on his expense report. Besides, did the man (Mike) even work one hour out there? It seemed the whole time he was wrapped up in beach fun and the usual Brady Bunch hijinks.
Anyhow, since I was a kid during most of the 1970s, I was not directly affected by Jimmy Carter, stagflation, gas lines, the Watergate farce, and leisure suits in fern bars, etc. I did suffer through disco, however, as I was becoming a teenager.
It was a fun time to grow up. We weren't tethered by smartphones, hovered over by helicopter parents, or subjected in school to sexual perversions like transgenderism or homosexuality. We rode our bicycles all over town (sans helmets) and got into plenty of mischief without hardly ever getting caught.
“ . I did suffer through disco, however, as I was becoming a teenager.”
Life is funny. I completely hated disco at the time of its popularity and even drove around with a “disco sucks” sticker on the back bumper for a year plus. You might not have liked it but you still heard plenty of it.
Fast forward 40 years and I got to the point of liking it because it puts me back into a better time when girls and mudding occupied most of my off time.