BIOS services are not used by modern multitasking GUI operating systems after they initially load, so the importance of the primary part of BIOS is greatly reduced from what it was initially in the IBM PC.
Modern OS do not rely on the BIOS to recognize the hardware but do it themselves.
The BIOS is after all much smaller than the OS and contains much fewer drivers.
The role of the BIOS is to read the operating system into memory and start it executing.
The most important role of the BIOS is to identify candidate boot devices.
To that purpose, the BIOS is usually customized to the particular manufacturer's hardware.
For a modern operating system its role stops there
and the OS will re-analyze the hardware and will correct BIOS failures or inaccuracies.
I believe it was in Vista that I first encountered a disk drive that the BIOS analyzed
as much smaller than it really was, but everything was correct after the installation of Vista.
As of 2011, the BIOS is being replaced by the more complex Extensible Firmware Interface (EFI) in many new machines.
The interface defined by the EFI specification includes data tables that contain platform information, and boot and runtime services that are available to the OS loader and OS.
EFI defines two types of services: boot services and runtime services. Boot services are only available while the firmware owns the platform and include text and graphical consoles on various devices, and bus, block and file services. Runtime services are still accessible while the operating system is running; they include mostly services such as date, time and NVRAM access.
ACPI aims to consolidate, check and improve upon existing power and configuration standards for hardware devices.
However, once power management is under the control of the operating system,
it takes over and has exclusive control of all aspects of power management and device configuration.
The OS then usually emulates ACPI-compatible system calls, but does not use the BIOS/UEFI for that.
See Wikipedia :
Unified Extensible Firmware Interface
Advanced Configuration and Power Interface