I think that people who say that history repeats are looking for patterns that don't exist and modifying them to fit their narrative.

The markets are completely different every time, but people want them to be similar so they say things like:

There's no such rule.
Since 2012 there were 7 or 8 crashes of 50% or more and 3 of them were over 80%, but that doesn't mean this one will be 80% again. Bitcoin matures with every cycle and becomes stronger with more businesses added, more hash power, more users and more institutional investors. If the bottom were to be at 73%, I wouldn't be surprised.

If you want to see how the market cycles change check the length of the bear markets. The time between a market bottom and the next halving was different each time.
364 days before the first halving, then 539 and 504. We are now 517 days before the halving, so is there a pattern? No, because the bottom could've been in June or still coming, nobody knows that, but the double top in 2021 proves to me that bitcoin does the unexpected.