From my experience, most FOSS software is very user friendly user-centric / user-focused, while proprietary stuff is shit. What is the most notable exception to this rule that comes to your mind?
Edit: With user friendliness, I don’t mean UI design, but things like how the software is handling user privacy, whether it sees its users as users or as money-making cattle, how it handles user feedback, compatibility with other software the user uses (vs. vendor lock-in), configurability, and similar issues.
Edit2: I was made aware that user friendliness is a defined term: https://en.wikipedia.org/w/index.php?title=Userfriendliness
The key to steam is that they realised that being user centric, while bad for short term profits is very good for long term profits. They are also not publicly traded, so not just anyone can buy in and try and make a quick buck burning them to the ground.
I’ve found their store and setup to be a reasonable balance of advertising to functionality. The fact that you can adjust it yourself is a good example of their mindset. Most people don’t care or find them useful. Those who don’t like them are unlikely to interact with them, so it’s not worth fighting their efforts to turn them off.