It might seem like an overkill but cycle accurate emulation is in many ways easier, just way less performant. Back in the day devs wrote software in a way that would leverage different timings between different pieces of hardware to achieve things that wouldn’t be possible otherwise like full screen parallax scrolling on Gameboy. Software emulators have to identify those cases and implement workarounds for them. Some edge cases are unresolved for years leading to bugs of varying severity. You can see a rundown of such cases on Analogue Pocket in this video.