To be clear, what Valve wants and claims to sell is a license as you describe, and maybe that is the story they sell to the game publishers using their platform

To be clear, what Valve wants and claims to sell is a license as you describe, and maybe that is the story they sell to the game publishers using their platform, and maybe it is all true in the US. What is actually being sold though depends on the jurisdiction, and Valve's bold claims have no teeth. It is common for US companies to learn the hard way that they cannot revoke legal rights in places like Australia and Europe. There is little point reading the license agreement when most of it is balderdash, falsely claiming a more limited agreement than that granted by law.