Yes to a large extent they got those monopolies by building truly outstanding products in good faith and by being pioneers in quite a few areas. And certainly they are an exemplary case of investing that wealth into legitimately innovative and widely appreciated long-term endeavors.
My point is that Valve is not all that special for being nice, many organizations do crave to be like that but they don’t have the luxury to have hit that jackpot. For people with mountains of money, they are among the best, but it’s not exactly a high standard, and they are remarkably inefficient in leveraging that advantage.
They’ve long lost the organizational know-how to make good games, and they have delivered remarkably few public facing successes in the last decade: mainly Valve Index and Steam Deck, both still relatively niche and wide apart, both primarily attempts at expanding Steam’s dominance to fairly uncharted markets, with mixed success. The first iteration of Steam Machines was dead on arrival, as was their long-anticipated game Artifact. CS 2 was not a significant enough upgrade to Go to really count. Half-Life Alyx was popularish I suppose. Anything else of note?