In MMT taxes must be used to withdraw money from the economy. Otherwise, there would be an infinite accumulation of money in it. Taxation, which takes money 'off the top' of income, thereby reducing disposable income, necessarily creates winners and losers, raising questions of fairness and arbitrariness. Besides, if raising taxes when necessary for managing the economy were a politically feasible idea we would still be living in a Keynesian world.

"Economic System Not the Problem" (here in Medium, but not behind the paywall) is an introduction to another monetary alternative (with links to more about it). It also involves creating money as needed, but the amount created at any time is strictly limited (by demographics--so demographics governs, passively but effectively, total output). It directly eliminates unemployment and poverty (at any level of total output) and funds (all) government without taxes (at the current per capita rate of total government spending)--as long as government anywhere does not exceed its allotted funding, at least. Money must be returned to its place of origin, but no money would be collected from any person or business before it could be used for purchases/investment. 'De-growth' is achieved without arbitrariness/unfairness---in other words, justly.