If owning stock (passively) all the sudden got taxed to any notable degree, you’ve just dramatically changed the value calculus for most of the world economy at this point. It would be shocking if the price didn’t crash.
That sounds like a one-time thing. Once things stabilize you wouldn't see a big fluctuation every time a CEO has to pay taxes.
Also normal people and the mildly rich and retirement funds and many other big sources of ownership wouldn't be taxed, so I don't see prices actually crashing.
Repeatedly pushing the "destroy the world economy" multiple times per day is most likely not going to be a "one-time thing". But who knows... maybe you're right and economics doesn't work like it has been documented to work by the world's experts for the last 100 years or so.
Also normal people and the mildly rich and retirement funds and many other big sources of ownership wouldn't be taxed, so I don't see prices actually crashing.