Probably not. I think there are calls for 90% taxes on all earnings over $100 million or so. Even with a 90% tax, there's still plenty of incentive to continue earning/building. I think the argument is that a person can reasonably be individually responsible for $10-100 million of value, but past that isn't realistic. Any excess value captured by one person is almost certainly actually being created by either their employees or by public infrastructure.
This 90% tax would really just be re-capturing that value by the entities which created the value (the taxpayers who work for the billionaire, and/or the government who built the infrastructure used).
I mean, if you were paid $600/hr since Christopher Columbus sailed to America and saved every penny, you still wouldn't have a billion dollars. It's really, really hard to say anyone has worked hard enough or created enough value on their own to justify a billion.
And a 90% tax over $100 million would still allow Bezos/Musk to have $30 billion each. Which is equivalent to a someone saving $1 million/year since the middle of the last ice age.