That doesn't seem to be the case here- Amazon's (and thus Bezos's) dip in early 2020 is practically invisible compared to its growth since then March, from what I see on https://finance.yahoo.com/quote/AMZN?p=AMZN
So...
Imagine you own a modest $300,000 house. A city inspector comes by and finds that your property is located on an old toxic waste spill- its value drops to $225,000. A week later, the city finds that they've made an error, and there is no toxic waste- and, in fact, that in doing the testing, they discovered deposits of incredibly valuable minerals on your property, so now your house is worth $450,000. A month after that, you get a tax bill in your mailbox for $45,000, 30% of your $150,000 asset gain. (These numbers are based (rounded) on the actual data.)
Please help me steelman your argument, assuming you aren't being disingenuous.
Lets say you owned 1 BTC since the inception ($0 cost basis) and held it until today. The value of 1 BTC has fluctuated the entire time, but you've only ever owned 1BTC.
Here are a couple lows/highs during the period: Dec 2018 - $3500 Jun 2019 - $12000 $8500 gain (on paper)
March 2020 - $5500 Aug 2020 - $12000 $6500 gain (on paper)
To use the Bernie Sanders standard of 60% windfall gains, you'd owe $5100 from the 2018 crash and recovery. If these types of windfall taxes become a common thing, you'd owe an additional $3,900 from the 2020 crash and recovery. So you'd have paid $9,000 to hold your 1BTC.
If you sell your 1BTC today, you'd get $10,000. With your $0 cost basis, the entire $10,000 is a capital gain. Lets say your long term capital gains rate is 15%, you'd owe $1,500 in taxes when you sell it.
So for investing in 1 BTC, you'd have $8500 in your bank account, and would have paid $10,500 to hold it.
1) Is BTC more volatile than Amazon stock: Yes 2) Does that amplify the numbers in my example: Yes 3) Is wealth inequality a giant problem in the country: Yes 4) Will I shed tears if Jeff Bezos gets a giant tax bill in the mail: No
However, I think it does demonstrate the problem with taxing the change in value of an asset, vs your capital gain from when you sell it.
An example I've been giving to people who are making the argument about billionaires making money during the pandemic is: Imagine you own a modest $300,000 house. A city inspector comes by and finds that your property is located on an old toxic waste spill and condemns it so that it is now worthless. A week later, the city finds that they've made an error, and there is no toxic waste, so now your house goes back to being worth $300,000. A month after that, you get a tax bill in your mailbox for $100,000, 30% of your $300,000 asset gain.