> Someone forgot to model growth in the value of the asset, and/or putting the wealth to use.
It's surprisingly not different.
If you have an asset that is dormant, is $100, and you tax it with 1% for 20 years, you get to $81.79 by calculating 1000.99^20.
Now suppose instead, your asset grows by 10% a year, and you have no tax. That asset grows to 1001.10^20 = $672
Now suppose that prior to the investment each year you tax it with 1% and invest the rest, for 20 years, again at 10%. So you get 1000.99^201.10^20 = $550
That $550 of $672 is exactly the same portion as $81.79 is of $100. In other words, growth or no growth, it has exactly the same effect, either way a 1% tax over 20 years takes 18.2%.
> Penalizing static value seems almost reasonable.
In the philosophy of taxation there's a different approach. Money you own is money you earned. Typically earnings are taxed. You produce X value, and a small portion of X is allocated to a general pot of money to fund general things in society, e.g. infrastructure, rule of law etc. But after that, it's your money. If you then invest it and earn more, again, a portion of those earnings are taxed. But if you don't do anything with the money, for the government to take it, is seen as a form of theft.
The principle why the one form of appropriation is okay and the other isn't, is because when you earn, you benefit. And the government benefits, too. When you just store, you don't benefit, and taking it is a purely negative experience. Many people are willing to share part of their new earnings. Few are willing to give up something that has always belonged to them.
Inflation is a natural penalty on static value anyway. So are opportunity costs. Plus, actually static value is quite rare, money in a savings account is being put to work by the bank. The amount of really static money (like money under your mattress, or a permanently vacant home) is quite a small portion of the financial system and again being penalised by inflation and opportunity costs already.