I don’t quite follow - what is the reason? That you wish there was a haptic home button? iPhones never had haptic buttons on the front face - only real physical press buttons.
iPhones had haptics home buttons from iPhone 7 and up, so if you’ve used even an old iPhone at this point it wasn’t a “real” button. Same as the MacBook trackpads, people can’t tell the difference.
For this reason, I’m totally fine with them doing the same for volume buttons. Also feels great on the AirPod pros