I don't know if the 4-year cycle is history or not, chances are it's not, and I still believe it works. The best reason I can find for the cycle to continue is: "don't break something that works". A counter-argument from the point of view of those with influence, would be that the more cycles we have, the more regular crypto investors learn about it, so... they need something new to trick them into giving up their good crypto assets. This argument is valid (not that it's moral), and steps have been taken every cycle to part people from their good crypto assets. Without breaking the cycle... for far.
We are talking about major projects failing or never being developed and taking with them the (majority of the) funds invested, hacks, early days in defi, NFTs, and now meme coins. All of them designed to take in solid crypto assets and produce sh*ty ones, if anything at all, for the most part and for most people.
Not a crypto chart, but it's perfectly cyclical...
One can think crypto ETFs or MSTR are blessings for crypto, but that's debatable. MSTR is leveraged investing in bitcoin using fiat instead of bitcoin, and will have a much bigger fall than BTC when things go south. Crypto ETFs are investing in crypto without the investors touching the underlying assets. Both of these investments are very susceptible to wider movements of risk-on assets, and don't stay in the space when things move toward risk-off.
From this point of view, something like setting tariffs by the US (or others, in retaliation) is seen as a risk off event, so prices going down leading to that and possible when that happens make sense. You can imagine what WW3 would be like for markets, except war and pharma stocks (the latter are doing well in peace or war, they don't care). On the other hand, a good (there's always the question: good for whom?) peace in Ukraine after all the recent events, will likely get the markets going up. Interestingly, the SEC dropping lawsuits one after the other has no effect on prices for the time being, when geopolitics is so tensed.
Another changing factor of the bitcoin cycle is the rise of stablecoins. Crypto people don't move to BTC to avoid risk or to take profits, they move to stablecoins. This could widen the rift between bitcoin investors and alts.
And guess what? BTC profits don't flow into alts either. They flow into stablecoins too.
And of course, the stablecoins will continue to rise and be pushed far and wide, since it helps the USD, or whatever the base currency is. It's not its competitor, a threat, and those in power understand this well now.
But this way, the "classical" seasons within the bitcoin cycle may change significantly. We don't know in which way yet, because there are too many factors to consider.