UBI is not luxury communism, or at least not any of the proposals I've seen. A guaranteed $1000 a month would help a lot of people, but $12000 a year is not a high income and many people will want to keep working to earn more money than that. Maybe they'd be able to retire sooner, though?

As for inflation, a lot depends on how gradually it's adopted. As we saw in the pandemic, supply chains need time to adjust and bad things happen after sudden changes.