The way that monopolies dominate is by stagnating tech. IT tech. The driver of our economy. You're missing a decade plus of killed advancements through acquisition and extermination. The efficacy gains are theirs, we just get to larp as being better by using them. The idea that HTML5, JS standardization, web assembly etc. are important is ignoring how they are simply abstractions that maintain the status quo and add complexity that only serves builds their moat.

RSS is probably the best example. This is massively more efficient than any other thing you mentioned, which are only incrementally better. RSS saves orders of a magnitude more energy than is "saved" by modern JS which requires ever more powerful processors where older computers are simply incapable of browsing the modern web, but for some legacy websites which really highlight how "efficient" these techs you mentioned really are. The only thing they are efficient at is extracting money from users into Google's pockets and selling new iPhones.

Newer processors, massive low power RAM banks, specialized IP processors, cutting edge lithography, Webkit, Chromium, all these advancements google now claims as theirs with your logic.