Valve has taken a less heavy-handed approach and let users have more freedom over their client and UI, but they also have a massive bot problem in titles like TF2.
I can’t connect to my work network from a random client, and it will throw flags and eventually block me if I connect with an out-of-date OS version.
I can’t present any piece of paper with my banking data and a signature on it and expect other parties to accept it. I have to present it on an authorized document.
I guess money may be the common denominator here.