364
Here’s how much Valve pays its staff — and how few people it employs
(www.theverge.com)
This is a most excellent place for technology news and articles.
That's the only one I saw that meant anything that useful. They have ~10x that for game development but no indication of number of people there, and 79 people working on Steam.
Number of employees working on games is in the list at the bottom of the article. 181 as of 2021.