Only taxing wealth "at rest" makes it avoidable for those who have the means to pay accountants to keep it moving in productive ways and thereby non-taxable. You then end up only taxing the people who can't afford that, which is the middle class.
If it's productive, it's contributing to society. If Alice's $100 goes to Bob's wages, which buys Charlie's shoeshine service, which pays for a week of TV dinners, I don't think those 100 dollars should be taxed more than David's 100 dollars that just sat in his bank account. But I do agree, we should prefer taxes that can't be avoided, LVT being the best option.