Which of them are privately owned? In a publicly traded company, there's an inherent logic that people who believe that the company can get by with squeezing customers a little harder will end up with higher projections than those who think it's better to get by with a moderate approach. Price goes up with the bids from the squeezers and occasionally a moderate will sell until eventually the squeezers own an identity-defining fraction. Valve only is what it is because of the ownership structure, its closeness to being bootstrapped (I assume that in reality ownership is a little more complicated, but close enough)

We could also call those squeezers "optimists", and publicly traded implies ownership by the most optimistic (well, the most optimistic who have money to invest). Leading to behavior patterns that could be described as suicidally chasing the most unrealistic money making projections. (and founder majority stakes are surprisingly susceptible to falling in line with those optimists, because those owners still don't want to see their valuation going down, doubly so of they ever started borrowing against their stakes)

"pretty quickly" is a few years, not one month. Chrome dominated the browser market pretty quickly even though the richer bigger company microsoft already had most of the browser marketshare, and that was 3 years. Before those 3 years it seemed like nobody would be able to make a dent in microsofts monopoly, and then it was gone in just 3 years.

If steams fumbles as hard as microsoft did with internet explorer they too could be mostly gone in 3 years, replaced by a giant competitors product.