I agree in principle but all the world is grey and “enemy of my enemy” and all that.

The actual monopoly posing the most threat is Microsoft and Windows. Valve knows that they are the underdog. So Valve supports Linux and Open Source and supports it like a non-monopolist would (because they are fighting the Windows monopoly). We all benefit from their efforts.

Zooming in, we benefit from a strong Valve because their strength becomes our strength (for now).

Zooming out, I agree that Valve’s position as the de facto App Store for games makes them dangerous. At some point, they may become a bigger problem than Microsoft. That is not today, in my view, but we need to be mindful. Valve is not our friend. But Valve is a better friend than Microsoft.