I sure as shit can't blame them - for a decade, Google tied Google Mobile Services (including things like Google Maps and the Play Store) to shipping Google's Android exclusively. If OEMs wanted to fork Android and drop Google for Microsoft, they'd (up until at least 2018) lose their license to GMS for all handsets sold. That changed in 2018 [0], when Google were told by the EU they would "... also need to stop preventing phone makers from using forked versions of Android" (from [0]).
I'm sure Google wouldn't pull any other licensing tricks to keep Microsoft or Huawei from making a competitive fork of Android now though! /s
[0] https://www.theverge.com/2018/7/18/17580694/google-android-e...