cutting unnecessary spending or increasing tax revenue

You are technically correct, but in a practical sense: lol good luck with that.

There are two major concerns I have with UBI.

1. It’s highly inflationary.

2. It fosters dependency, and it’s an economic-political death spiral. People on UBI vote for those who support higher UBI. Inflation increases due to increased monetary velocity. People demand higher UBI due to cost of living increases. Votes go to those who promise higher UBI, etc. The cycle continues until you’re wiping your ass with currency or some form of CBDC is implemented to stop the bleeding.