Deliver fake data would be an insanely dangerous game from Valve: that data is what all their partner to make strategic choices... if there's any proof of that, all their partner would drop the ball and Valve would lose it's multi billion business in just few weeks.

2. fake that data is plain stupid too: Valve has all the interest to know and share where is the bigger pie piece... so Capcom, Sega, Blizzard etc. can tune their product. For example, let's say Valve goes crazy and say that the GPU Nvidia RTX 5090Ti got 50% of market share... and all their partner follow this fake data and deliver all their products with no optimizations: results for their customers? (and, before any one mention it: yes, this apply the opposite: if Valve say 50% of GPU market share are shitty old Intel iGPU... all future games on PC will overly tuned towards the lowest end and big publisher won't even bother trying with next gen videogames).