Your observations is correct, but it also depends on other factors. The instruction timing and such fiddly low-level details is most visible in systems program

Your observations is correct, but it also depends on other factors. The instruction timing and such fiddly low-level details is most visible in systems programmed in low level, such as older consoles. Modern systems tend to be programmed in higher level languages, which works much better to HLE (high-level emulate), since they tend to be programmed in a way that cares less/not at all about underlying hardware fiddly details. So when you are emulating the NES, these details matter way more than when you are emulating the Switch for example.