In the olde days of the early Personal Computer, the BIOS-based firmware’s default bootloader would be a resident BASIC interpreter REPL. Companies made money licensing that BASIC interpreter to vendors!

So a built-in default BASIC interpreter bootloader app was one feature that BIOS had which UEFI did not. ….until now (and this one is not closed-source):

A BASIC interpreter for UEFI.

https://github.com/logern5/UEFI_Basic