Chess.com has a measurement for how accurate a player plays compared to top engine moves called Computer Aggregated Precision Score (or "CAPS"), and top humans do play incredibly accurately. Magnus has CAPS of 98.36 for example.
I think that as a measure of skill vs. a computer that statistic doesn't tell you all that much. Note that even in that measure Magnus only picks the top move ~85% of the time, and that includes many moves where the top move is "obvious" which will inflate the average a bit. And it needs to be kept in mind that Magnus cannot win against a modern computer, so clearly that 85% only means so much, computer play is still on a whole different level from human play.
Beyond that, time is a very important factor, running out the clock is one of the most effective ways to win against cheating opponents. Magnus only finds the top move ~85% of the time and takes probably 10x to 100x the time to do it. And like the other commenter noted, variance in the move time is an extremely obvious tell. Magnus will blitz out certain moves (even in classical chess) and then think for ~40 minutes in other complicated positions. A computer can do both positions in basically the same amount of time, and cheating players typically don't know when they "should" be thinking vs. playing fast.
Note that even his "top engine match" is 85%. This is not a fantastically high number, given that maybe 40% of moves are obvious/must-moves. I bet I match the engine ~60%.
I also think this is his classical games, not rapid, blitz, or bullet.
Top human players tend to make safer, lower variance moves than things engines prove super safe on evaluation. They may give up a few centipawns for ease of analysis.
Beyond that, time is a very important factor, running out the clock is one of the most effective ways to win against cheating opponents. Magnus only finds the top move ~85% of the time and takes probably 10x to 100x the time to do it. And like the other commenter noted, variance in the move time is an extremely obvious tell. Magnus will blitz out certain moves (even in classical chess) and then think for ~40 minutes in other complicated positions. A computer can do both positions in basically the same amount of time, and cheating players typically don't know when they "should" be thinking vs. playing fast.