It was a ver common phrase. I think its been lost to history but right before "TikTok" the phrase "tic tock" was getting popular as a way to say, "the second-by-second run down", e.g. give me the tic tock.
I believe that by the end of the century half of the most common words of the English language will have been hostilely taken over and ruined by tech companies.
>I feel like the most popular pre-app wide popular usage would’ve been the Ke$ha song.
Agreed, a lot of the alternative usages that people are mentioning seem fake and I don't recall any of them being a thing. The only usage I recall being widespread was people saying tick tock to tell you to hurry up implying that the hands of a clock are moving. That and the little known novel from the 80's about a sentient murderous robot.