Well, there is a point to UBI.

Right now, we have the system set up where the majority of people work to live.

That means your average person's ability to consume goods, spend money, and be an overall contributor to the economy depends on them being employed the majority of the time.

If you break that connection, you could have major issues. The numbers can't go up if people can't buy things. So, if entire sectors automate rapidly, that could get... interesting.