That's surprising, I have a '23 X6, and the built-in navigation is actually really nice. The maps have more detailed information than both Google and Apple Maps in many areas. I also haven't observed any lag/stuttering, but perhaps the hardware is worse or something on newer models.

Anyway, for me at least, the benefit of the built-in nav is not about routing, which is basically always worse than Google/Apple at this point, but about having detailed, offline maps. In my experience, offline Google/Apple maps are less detailed, and you have to download them in advance.

I use all three, depending on my needs at the time - each of them have their strengths. I prefer Google/Apple maps for day to day routing and things like that, but if I'm somewhere with poor signal, I use the native maps to navigate, because they are just more reliable.

It's all subjective though, and probably highly specific to location.