Only because of halving. Otherwise it would not be so predictable.

Eliminating halving was one of the core goals of the cryptonote protocol that is the basis of Monero, in the whitepaper for cryptonote it discusses the issue of the security vulnerability created by it, as it forces miners to shut down at least half of their capacity for a while due to the halving of block rewards. Less miners = less secure.

We are past that point, and as that whitepaper predicts, the market does not like halvenings that's why it takes nearly a year for the market to return to normal. Right after halving, usually there will be a big sell-off from miners which is why the price was depressed at 8-9000 for the last 6 months. That's the mechanism at play.

Note that the graphene chains do not have halvenings, in fact a large number of PoS chains don't have them. Their price action is consequently less stair-stepped also, and less predictable. Eventually bitcoin will lose its privileged position because of the antiquated protocol features especially halvings.