Healthcare: Some people get unlucky with genetic lottery and will require far more cost in care than others. Some type of universal coverage still needs to exist imho.
Social security: Unfortunately, not everyone is good with money. Social security is a mechanism for balancing out and restributing wealth, but it's also an investing service for those who don't know how to.
I'm not against some type of UBI, but there are some downsides with getting rid of existing programs. imho.