Engines have contributed substantially to modern opening books but they haven't supplanted the existing knowledge. Humans turned out to be wrong about many sharp lines (which were refuted by computer) and the computer can find really interesting ideas in many positions (which would be nearly impossible for a human to find) but the old human-approved Best Openings are still standing tall after the engine revolution.
This may have been true when engines were still only marginally stronger than humans, but I haven't seen any evidence that is currently true. A few years ago Nakamura + Rybka (previous best program) lost to Stockfish.
The strongest players are not GMs, as far as I know, and a very important part of those games is trying to force positions where the opponent's engine might make a slight mistake
Here is an interview with the world champion https://en.chessbase.com/post/better-than-an-engine-leonardo...
Anyway, I was just making a slightly facetious point that all our existing openings came about by a slow, semi-random process in which people tried moves, played out the games, and then looked at the results.
Usually "real evidence" that the human choices sometimes are better than the machine ones is that the engines after a long time agree with the human choices.