I have owned BMWs since 1977 and have had 18 of them. I have had my M4 for 4 years now and has only had oil changes. I have had my Z3 for almost 18 years and have had to replace the top and the A/C compressor. All the other ones I had, except for one were equally as reliable.
Sorry you have had the problems that you have had, but I wouldn't judge BMW by your 7-series. You might want to check this out with regards to reliability:
https://www.businessinsider.com/most...-6-chevrolet-6