PG's only argument was that the tax compounds, and completely ignored the fact that wealth compounds much, much faster than tax burden grows.
Someone who inherits $3 million (not much from the point of view of the very-wealthy) can live comfortably on the growth alone while still compounding their wealth further every year.
The only way a wealth tax would compound faster than the wealth itself is if it is larger than the growth rate of the wealth. And since the growth of wealth (e.g. by just sticking it in an index fund) has averaged at ~8-10% over the past several decades, a 1% tax is not going to eat into a person's wealth over time. It's simply going to slightly slow that growth down.
The rest of the article on how PG's essay involved a slight of hand was interesting, I had missed that.