But when pushing/folding, there are optimal charts. It's just that you need different groups of charts against loose or tight opponents ))
And not even when pushing/folding, there are charts for stacks of 100bb, 40bb, etc., obtained with various solvers, which work very effectively against unknown opponents.
Even according to Harrington's book, you can make a chart for the early stage of the tournament. He details everything in percentages, how to play which hands from different positions in different typical situations.
And the corrections for the opponents' game are already a more "subtle" game...
P.S. For example: