> But Graham's math is only applicable to those flush with investments and with relatively small salaries from labor, so a wealth tax is only unpopular to that particular group.

Not quite, because you're using the opposite extreme where someone has no assets. Meanwhile the median net worth in the US ~$200k, which would be $2000/year in tax for every 1% in wealth tax. That's certainly enough for ordinary people to notice.

On top of that, the conversion is even worse than that implies for ordinary people, because the primary reason the median is ~$200k isn't that the median person has $200k their whole lives, it's that they have ~$0 when they're 18 and ~$400k when they retire and the median person is about halfway to retirement age. If you transfer tax burden from income tax to wealth tax then that means they'll be paying more in wealth tax in the second half of their life, which means they need to be saving rather than spending the money not paid in income tax, including during the first half of their life. But that causes their net worth to go up on paper by more/sooner, because they're essentially holding extra money they'll only have to pay in tax later, which in turn causes them to pay more in tax for a tax on holding assets.

Moreover, then you can't say that Alice always benefits because she has no assets and Bob always pays more because he has $400,000 because what's actually happening is that Alice pays less when she's 20 and more when she's 60. That's going to be unpopular because the 20 year olds are generally expecting to be 60 someday but the 60 year olds never expect to be 20 again.