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Microsoft to stop forcing Windows 11 users into Edge in EU countries
(www.theverge.com)
This is a most excellent place for technology news and articles.
Valve is and was aware of this problem even back then. I don't have a reliable source on this but from what I remember it all started when Microsoft begun pushing the Microsoft Store.
Gabe Newell even said Linux is the future of gaming
And for this I have a source: https://www.pcgamer.com/gabe-newell-linux-and-open-source-are-the-future-of-gaming/