I would prefer to fund it via a land value tax, which is seen as the most efficient form of taxation due to having no deadweight loss.

Like the other commenter said, the concept of a UBI is already practically the reality in countries with strong welfare states where no one technically needs to work. We just disguise it with all this means-testing because as a society we're still devoted to this pro-work capitalist grind mental model of everyone needing to make a buck to justify their existence.