Honestly? Google.
For me, it's not about whose the bigger scarier influence, or who does more evil. It's just based on how practically I see either turning out.
=Microsoft Acquisition=
For a few months to a year, everything is mostly the same, until new features start happening. It starts with something like annotations on particular regions of code, with say all the annotations for the codebase stored in an extra file "git_annotations.tla", which is some zip file collecting together a bunch of random undocumented xml that changes constantly. These annotations are tracked semi-competently by VS Code and MS team enterprise tools, being updated to deal with source changes with each commit, but ultimately just showing up automagically in either the web view, VS Code, or associated enterprise tools. These annotations will start out as minor unimportant things, not even really worth porting to other editors, but will increasingly be abused for code review in enterprisey contexts. People who try to just edit things from the command line or their editor of choice will be constantly breaking other people's annotations at random times since they don't update that file, so file renamings, moving, etc won't be tracked properly. MS provides some xcode/sublime/atom plugins to provide partial support for some other editors, which prompts web developers to adopt them in droves so they can add gif tooltips to comments. At no point is there a great enough reason for anyone still using github to switch, so slowly the remaining open source projects there start making use of these features, and so contributers need to start using the appropriate MS tooling to ensure their commit doesn't break the annotations (or just use one of the supported editors).
=Google Acquisition=
Github user profiles are now linked to a google account. The webclient works better in chrome than other browsers. The webclient is renamed, rebranded and redesigned every 2-4 years by someone looking for a promotion, but ultimately in a way that doesn't affect people just using git from the command line. Github possibly gets a few additional features to support internal usage with Google weird mono-repo lifestyle. Google tries unsuccessfully multiple times to integrate Github into yet another failed team messaging platform or whatever, but again in ways that only affect the webclient. Google more successfully does some data analytics stuff based on searching and indexing all of that code now sitting on servers they own, and this is almost but not quite profitable, but close enough for them to leave it alone and get distracted by something else that's shiny.
To me, neither seems ideal, but all of the annoyance of the google stuff seems avoidable by just using separate accounts for separate things, as usual.