You'd need to also tax gifts and inheritance at the same rate for that to work. Also, because of the time value of money, delaying tax on wealth allows you to grow it more effectively. Even if the money is eventually taxed at X%, you had years or decades for it to compound first while people who need to spend it now don't have that opportunity.

Well, first, no, they don't. Gifts, inheritance, spending it via "charitable" organizations, or better yet spend in lower tax regions. We have multi-generational trust fund families.

Secondly, they can accumulate more wealth much faster than they can spend. Plus they can play with things on a longer time horizon and move internationally. Like, say once the sales tax drops.

Not without an inheritance and gift tax of 100%, and not if they invest it.