>That is an existing problem inherent to any tax system. It's just saying "Rich people can afford to not spend all of their money". I don't see how that's fundamental to taxing only spending.

If you taxed only assets it wouldn't be a problem. Mo money mo taxes.

Whether you want to tax predominantly assets or spending usually reflects which side of the capital divide you see yourself identifying with - predominantly a recipient of unearned income (e.g. landlord/FIRE) or a payer (e.g. renter).