but why is it then so many BMW have issues? I have to go to my Benz dealership quite frequently too. Toyota/Lexus - zero issues.
Because BMW and Mercedes are pushing the envelope in technology. Lexus and Toyota stick with old technology. It makes their cars less pleasant to use - older infotainment, worse performance - but they are more reliable. Different values.
They're also simpler when it comes to options. I had an Audi once and it had electronic everything, including adjustable lumbar support and heated seats. With these kinds of cars, if an electrical component dies you'll likely have to take the car to the dealer to get it fixed.
that makes no sense, most of the issues were with the engine. Toyota/Lexus: zero issues