For me it’s much easier to lock the phone by holding any volume and power then to remember the sequence needed to force power of the phone.
Clicking 5 times on power is probably faster, but I forgot that existed and if I’m trying to do something quickly essentially squeezing my phone is easier than trying to tap the correct side 5 times quickly under pressure. And much easier to me then trying to remember the force power off sequence and performing it without looking under stress.
Especially on the iPhone 15 pros there is now another button so getting the up down up power means finding the correct up button.
I’ve looked up that sequence numerous times when I’ve needed to force reboot and I still forget it half the time.