When a monopoly is faced with a smaller, more efficient competitor, they cut prices to keep people from switching, or buy the new competitor, make themselves more efficient, and increase profits.
When Steam was faced with smaller competition that charged lower prices, they did - nothing. They're not the leader because of a trick, or clever marketing, but because they give both publishers and gamers a huge stack of things they want.
Sure, Steam seems fairly okay, especially their Linux support, but I still mostly prefer GOG, wherever possible, because it offers more control to their customer over the product they bought.
It helps that Valve is not publicly traded, but I fear that if the current owner (Gabe Newell) dies, there might be a shift in business practices.
Enshittification can still happen in privately traded/owned companies, it generally happens slower and in case there are other reason for the owner(s) to maximize short term profits (e.g. business built on VC money), it can happen faster.
Gog support sucks tbh. Steam refunds everything no questions asked. Bought elden ring on gog, wrong region, couldn't activate it back home. They told me to suck it. Fuck gog
Gog is also much easier to deal with via a VPN. I bought some region locked games easily doing that and could play them anywhere, because they are DRM-free. Steam is much more difficult, because each account belongs to a specific region. Moving accounts means you have to have an bank account and address in different countries, so easy for rich people, more difficult for ordinary folks.