OpenAI. In my eyes, Google’s power is entirely in a) assets, b) an army of geniuses, and c) a brand that lets it maintain ubiquitous monopoly status over search ads. Google does a lot of other cute stuff, and they desperately want another revenue stream, but the simple truth is that the entire core of the company’s whole operation is search ads. Display ads are on the way out due to privacy concerns, and OpenAI has damaged both b and c.
I think that c might be inverted. It's the economic power/performance of their search ads that let them maintain a brand rather than the other way around.
To clarify: I think the reason Google control search is that the public likes Google, so there's no political will to enforce the law. It's starting to crack now with the "google search is bad now" narrative, along with the classic "google is spying on me" -- together, they've emboldened Biden's justice department enough to bring multiple suits.
I think Google's attitude of free products (Gmail, Google Maps, Android, and Chrome especially) has won it insane amounts of goodwill, and that's all that's keeping them at the top. Having worked at Google, I find it incredibly hard to believe that they have any sort of fundamental technical advantage when it comes to building a search engine. I didn't work on search and obviously didn't look for the secret sauce, so that assessment is based on company culture and attitude alone.
