> Can you substantiate this?

Since the topic is WASM here; here is the webassembly working group: https://www.w3.org/groups/wg/wasm/participants

15 Google, 7 Microsoft and rest are 1-2 seats max.

WebRTC https://www.w3.org/groups/wg/webrtc/participants

22 Google, 12 Microsoft, 7 Mozilla, rest are 1-2 seats max

Web Performance https://www.w3.org/groups/wg/webperf/participants

32 Google, 10 Meta

And the situation is similar in most groups: https://www.w3.org/groups/wg/

I agree that making the web work better is good for Google. But making the web good and advertiser friendly even at the cost of users and their privacy is better for them.