Which blacklist please?

True but you can do that for consoles too (PS5 not yet), and this issue isn’t what makes them not a full PC.

The fact that steam games are cross platform is because you buy a license. Very rarely a cd-rom would have Mac and Windows in one, but in that regard desktops were mostly like consoles not so long ago.

How would you do this without verification? How do you still allow gift tickets or buying for a friend?