The four year cycle was initially caused by supply shock of the mining reward halvings, but the subsidy is slowly being overtaken by transaction fees. Over the next cycle, the fees might overtake the subsidy in the macro, and then the cycle is nearly only due to the memory of the investors and not a real market mechanism.

I wonder if bitcoin had a steadily reducing subsidy, and the rate of decrease itself decreased, producing a continuous rather than step function over time, if that would have been better or worse.