First, thanks for posting in these P&S threads. I've had some great discussions with you in the past, and apologies if my posts come across as combative, because that is not the intent.
But capital gains tax affects everyone with any assets, it's not restricted to the rich. Same as income tax. Normal people tend to pay these taxes, whereas the ultra-rich don't, because they are able to pay people to employ accounting sleight-of-hand and exploit legal loopholes, and also move money/assets between jurisdictions. It is difficult to get the ultra-rich to pay any form of tax. I'm sure they would try to avoid (or evade) a wealth tax, too... but that doesn't mean we shouldn't try.
There is potentially a considerable difference between being "not very much against" and being "in favour"... but if as a theoretical game we assume that you want billionaires to pay more tax, what would you propose? A tax on assets above some astronomical threshold seems to me to be a good idea. But I would certainly be interested in hearing alternative approaches.
It's rare that we hit upon a point of difference that can be quantified, but here we have one. It is absolutely not the case that the middle class is where the money is. I think a part of the issue is that our evolutionary heritage means that human brains can't readily visualise big numbers. Please please do me the favour of scrolling across the data visual that I linked to above, you may be surprised - and it is always good to challenge our assumptions.
But if you really don't want to, then the screengrab below from this video may give a taster. It shows the ideal (apparently according to 92% of Americans) vs what they perceive as reality vs actual reality. It's 10 years old, and the situation is even more extreme now than it was back then.
It may surprise you that my personal ideal would actually be more unequal than the 'ideal' in this video. In principle I would not be overly averse to the perceived actual, if it could be adjusted slightly to move the lower end some way above the poverty line. But actual reality is just obscene.