There are a lot of parallels: It has a janky set of buggy drivers. It has backslashes in paths. It has a shell that is "inspired" by COMMAND.COM. And it's basically a program loader where every program immediately replaces it and drives the hardware directly.
Except that UEFI supports loading PE executables which replace it and have direct access to hardware… so… not really BIOS-like. Some UEFI implementations provide BIOS compatibility, but that’s via an UEFI application whether provided by the implementer or via something like CSMWrap: https://github.com/CSMWrap/CSMWrap
