Why is PC BIOS still such an absolute shit show? Seemingly similar products from the same brand will have wildly different BIOS options and functions. Want to

Why is PC BIOS still such an absolute shit show? Seemingly similar products from the same brand will have wildly different BIOS options and functions. Want to auto power on? Good luck with support for that being documented anywhere, and even if it is documented, the odds that the actual unit supports it is 50/50 at best it seems. Want to customize boot options? You may or may not get the options you need. Fan speed controls, clocking options. Every unit seemingly has been shipped with its own unique set of BIOS options supported, no two are ever the same.