If you do not want those features, that means that the OS is not intended to be used on a personal computer, but only on an embedded computer.
For dedicated embedded computers, the purpose for an OS becomes completely different and compatibility with anything does not matter any more.
Not only personal computers cannot be used without a huge amount of device drivers, but even for a very simple server, e.g. an Internet gateway/router/firewall or a NAS server, the amount of work for writing the device drivers, the file systems and the networking part would be much more work than writing the core of a new OS.
Only for embedded computers the work needed for device drivers can be smaller than for the base operating system.
Not every hobby OS needs or even wants networking, gpu support, even storage I/O, etc. See TempleOS.
The goal typically isn't to make a fully featured OS.