BIOS was always heavily tied to x86 PCs, as it was a de facto standard in the first place by the fact that it was reverse engineered from the IBM PC. Of course, PC-compatible firmwares were never required for x86 PCs, but it made it convenient in the era when people would bring their own OS. When ARM started becoming popular, it was generally in embedded applications where the manufacturer was going to produce a single firmware to do a single task. It's only lately, since UEFI became the standard on x86-type computers, that anyone's bothered making a general-purpose enough ARM device where you might want to bring your own OS and that UEFI has been something that would be useful there

> Does anyone still use UEFI?

Yes. It's extremely common.

> If I start looking into the latest and greatest Qualcomm Nuvia ARM Windows laptops, does it use UEFI?

Yes, those use UEFI.

> Or regular BIOS?

Almost nothing widely produced today uses old "regular BIOS". Even those which seem to use "regular BIOS" are largely UEFI systems acting like a legacy BIOS. Even things like Apple MacBooks which don't use EFI use an Apple custom similar firmware concept far removed from legacy BIOS.

> Does anyone still use UEFI?

Only 99% of all non-embedded computing products that are faster than a few hundred MHz.