How is that bullshit? People do like to give promotions to other people they like, sometimes irrelevant of talent. Look at literally all non-democratic governments.
And it’s no secret random conversations not about work happen a lot more in person. These are the kind of conversations that make friendships, not the 1 on 1 with your manager on teams.
This is why most sane companies don’t force you to do 4 days but instead make it so that if you only have to do 2 days at the office, they’re the same 2 days of the week for everyone to avoid the situation in this post.