Imagine your UBI money become $500 in a day or transaction fees suddenly raise to $10, that'd be disaster for people who barely make a living

Or imagine an average citizen googling "download Bitcoin wallet" and falling for one of those fake malicious wallets, because they don't know that you first have to verify the site and then the cryptographic signature of the developer. Or how their exchange account would get hacked because their password is their cat's name. I think 99% of the population is simply not ready for Bitcoin because of their security habits.