Yes it seems that E46 is a great car and one of the easiest car in its class to work on, but it does not make it any more reliable. Check this BMW E46 car owned by one of Throttle House's presenters (one of the popular car channel on YouTube with 1 million subscribers), and watch on how his never ending complaints and ramblings about how unreliable is the car [1]. Compared to the Myiata car shown in the same video, the reliability is night and day. Granted it is a newer Myiata but even a similarly maintained 20 years old Myiata will be much better than the 20 years old E46. There is a reason why Mazda is considered one of the most reliable car brands in the world today [2].
There is also a reputable story where Toyota's engineers had to delay their Supra development that is based on the BMW Z4 (or comically known as Zupra) due to the lower standard of components being used by the BMW engineers [3]. The culture for car or vehicle engineering in Germany are notorious for favouring the high performance rather than the high reliability. The were also some of the historians that claimed World War 2 ground battles were won due the cheaper and more reliable Russian made T-34 tanks compared to the over complicated and less reliable Panzer tanks by the Germans.
[1]https://youtu.be/wlNkfaNcbNM
[2]https://www.motorbiscuit.com/how-mazda-outranked-toyota-and-...