That’s not true. You’re thinking of social programs. Socialism is when workers own the means of production.
If this was socialism, America would have already done a military coup in Denver.
Socialism, in an extreme simplification, is a mode of political and economic organisation in which the workers own the means of production, and receive the full value of their labour. While social welfare programs are often attached to that, they are not socialism in and of themselves, nor are they a prerequisite to socialism (but it is nice to have).
Inherently, the funding of social programs must be derived by taking value away from capital and redistributing it to the public. In general, social programs might not be socialist, but in the particular case of UBI it’s literally a direct redistribution of (some) surplus value from capital accumulators to society. Just like how the term “capitalism” today doesn’t describe a perfectly capitalist economy, the term “socialism” has been co-opted to refer more to progress towards socialism… In that regard, I think UBI programs are distinct from typical social programs (i.e. expanding universal healthcare further does not make a society socialist, nor does improving support for homelessness) in that they are direct progress towards socialism (i.e. expanding UBI further literally redistributes value entirely from capital to society and basically achieves the goals of social ownership).
