The arcade cabinet repairman down in the comments has an interesting perspective. When the machines were new, behavior of the ASICs would've been incredibly important; hard to build a good knock-off if the original dev did something impressive using custom hardware. It seems to me like most of the benefit of that is eaten up by the sheer power of current hardware, though. It's more feasible to brute-force your way through things in realtime in software than it would have been then.