https://en.wikipedia.org/wiki/Architecture_of_Windows_NT
"The Windows NT 3.x series of releases had placed the GDI component in the user-mode Client/Server Runtime Subsystem, but this was moved into kernel mode with Windows NT 4.0 to improve graphics performance.[23]"
Note NT 4.0 appeared a year after Windows 95. The programmers had the benefit of using Windows NT even before 95 appeared, but the advantages of 95 were clear for the "normal users" who didn't think they needed the "protection" aspects: the most popular software of the time (e.g. Microsoft Word) was unstable enough to, from time to time, crash even on NT. The more stable Word versions appeared only after the famous Gates' 2002 memo started to be applied to the Microsoft Office products:
https://en.wikipedia.org/wiki/Trustworthy_computing#Microsof...
Windows 95 was for a time a good trade-off for many practical uses.
Windows 95 used its own 32-bit file system code whenever possible:
https://en.wikipedia.org/wiki/32-bit_file_access
It had to fall back to call BIOS only in special cases, as a backward compatibility for some older hardware/drivers. So even if you would launch it from DOS, it would for most newer hardware be just a bootstrap phase.