> Hardware has grown exponentially in complexity since Linux was initially developed of course, which makes the job of writing a new OS much tougher.
Though, interestingly hardware also got a lot smarter (because usually they have some kind of microprocessor and RTOS on them), so in theory interfacing with it should be more easier. (Serial buses, simple enumerate, simple addressing, we have a lot of good abstractions, no need to fiddle with registers, just use a PCI-E, DMA, I2C library.)
But of course at the same time just supporting these smart standards is hard (because initialization of things is not trivial, even just getting DDR RAM to work requires tinkering with MSRs, and ACPI is its own special hell).
Though, interestingly hardware also got a lot smarter (because usually they have some kind of microprocessor and RTOS on them), so in theory interfacing with it should be more easier. (Serial buses, simple enumerate, simple addressing, we have a lot of good abstractions, no need to fiddle with registers, just use a PCI-E, DMA, I2C library.)
But of course at the same time just supporting these smart standards is hard (because initialization of things is not trivial, even just getting DDR RAM to work requires tinkering with MSRs, and ACPI is its own special hell).