In general I fully agree except with your conclusion. In the short-run efficiency immediately benefits the established players, but in the long-run it benefits, more or less literally, everybody except them. Because as you bring the price down on things you enable more efficient competition. Competition increases, margins decrease, baseline minimal standard of quality for success increases.

Software is a very clear example on this front. Valheim [1] is a game that was made mostly by one guy, at first at least. Not that long ago, this would have been a multi million dollar game produced by a wide array of people. It's just that tools, markets, and more have made it possible for even single developers to have an absurd degree of efficiency. And LLMs are probably going to bump this up exponentially.

This is why a metaphor I'm currently drawn to is one of people living in a very agrarian society just prior to the Industrial Revolution. What would they have envisioned being created? Super farms of course. And those super farms were indeed created, but the overall impact was such that those super farms became a practically inconsequential part of the overall economy. The future we're moving into isn't going to be the same but more efficient for those on top. That efficiency is going to revolutionize the economy in ways that are probably impossible to see from a distant, much how somebody living in an agrarian society couldn't have even begun to imagine the 'real' impact of the Industrial Revolution.

[1] - https://store.steampowered.com/app/892970/Valheim/