His net worth peaked at $100M right before the 2008 financial crisis, which apparently decimated his investments.

If you spend a lot of money without paying your taxes, you still owe those taxes, which means you have significantly less money than you think you do. So when his aforementioned wealth peaked at $100M, the real value (i.e. minus taxes) was probably much lower.

Not withstanding the amount, I'm willing to be corrected there, but the latter part makes little sense:

Say I have $1M in the bank (or in Bitcoin), but I owe the IRS say $300K.

I leave the country, and take my money out of the reach of the IRS.

My "net worth" on an accounting statement might be $700K, but if I'm making a point of avoiding and biting my thumb at the IRS, I still absolute have access to $1M, regardless of moneys owed or claimed. And if I have no intention of paying those taxes, I'm certainly going to use that money. And McAfee was very actively saying "I'm keeping that owed tax and doing whatever the hell I like with it".

The IRS can seize assets. McAfee wasn't sitting on $100M in hard cash, most was in property and investments.

According to [0] he was down to about $4M in net worth after 2008, which isn't nothing, especially in a LCOL country, but for context, if he made 200k per year and put 10% away for retirement from when he was 25, he would have had the same amount.

[0] https://www.therichest.com/celebnetworth/celebrity-business/...

Given that McAfee himself claimed he had assets seized by the feds and had nothing at the end, I don't think even McAfee was ever as far out of reach as you think he was.

Suppose your assets lost 70 percent of their value soon after the tax year ended. Now your net worth is 300k while your tax bill is 400k, and you can only slowly get the over-payment back by deducting it against your current taxes.

We are assuming McAfee is just not paying taxes because craziness, but when you have volatile situation you can get burned by the rules pretty badly.