What are the consequences if trump is allowed to pick and choose what is funded?

So the trump administration seems to think it has the power to just decide things they don't like are waste fraud or abuse and stop funding them..

Close down entire agencies without any legislation...

https://www.pbs.org/newshour/politics/thousands-begin-forced-leave-at-usaid-under-trumps-plan-to-gut-the-agency

trump has created a sovereign wealth fund to spend the funds however he sees fit.

https://www.reuters.com/markets/wealth/trump-signs-executive-order-create-sovereign-wealth-fund-2025-02-03/

What would be the point of Congress in this new world? I mean they vote to fund a program, but then the executive branch just says "no' well use that money on something else.

Would this represent a huge shift in the form of government in the US?