For a very long time, BMW's cars were intentionally driver-centric - if you got a BMW, you were getting a car that was luxurious and well built, sure, but more than that, was just sublime to drive in a way the spec sheets don't capture. The handling, steering, suspension feel, engine and transmission, everything combined for something that was engaging and genuinely fun to drive, but didn't sacrifice actual daily usability. That was their sales pitch: Want luxury? Grab a Benz. Care about the actual driving experience? Here's your car.
I really don't know what happened after 2005, and it wasn't overnight, but the general driving experience of the cars has declined every generation since then - steering's gotten a bit more numb, suspension's not quite as communicative, engine noises are more muffled, and they just seemed to lose the thread over the years. I'm not sure if some of it was leaning into technology at the expense of the driving experience, but aside from the one or two models per generation that still have some of the old soul, they really don't seem to know what their sales pitch is anymore.