Most of the features of a modern BIOS are useless* anyways.
BIOS companies, universally, produce nothing but shit. BIOS are horrible programs. Bloated, terribly written, slow, unreliable, and cause all sorts of horrible problems with Linux. Nothing but shit. Almost every single one.
EFI is going to be better... but it's terribly designed. Over engineered horrific mismatch of 'this sounds cool' design-by-committee mishmash. A terrible abortion brought to you by megalomanics from from Intel and Microsoft.
* Has it's own shell.
* Requires a built-in EBC interpreter
If that gives you any idea of it.
It's like ACPI, except much more.
What we really want is our operating system to control the hardware. No matter what EFI or BIOS does to setup the hardware it will have to be re-done by the kernel anyways. In fact it makes things worse because not only you have to setup the hardware correctly, you have to figure out in what stupid brain-dead thing the BIOS did to break it.
Coreboot has the advantage that you by-pass all that stuff and just have Linux configure it the way it should be right off the bat. Linux needs to work on the hardware anyways. So getting Linux to work means that you are getting Coreboot to work.
For systems that want to still see a BIOS coreboot can throw a fake one at them, like SeaBIOS.
Unfortunately the worst thing against Coreboot is that it's not going to be liked by Microsoft and friends. So always using Coreboot means extra work.