Let’s assume that it would only take 1% of the population to meet all the physical needs of the world, why should they GIVE anything to the other 99%? Which is what a basic income is doing, you’re taking from those who work and giving it to those who don’t. Would it not be better to take that human potential to do things? Look at the art, music, research, that we aren’t currently doing because people must make a living. There are plenty of worthwhile things that we aren’t currently doing because of the cost, so instead of a basic income, have people work at things they are passionate about. Love to garden, that’s your job, it wouldn’t matter how much or what you produced as long you were productive, same with art, music, research that would be your job, for which you’d be paid, with the goal of improving ourselves and the rest of humanity.
The thing is, you are already giving good points about how basic income will make a better society. With basic income people will be able to do what they love, without worries about feeding, having shelter, etc. But, they would be paid (as they are now) on top of the basic income, which takes to an ever greater benefit. Those who have a moderate amount of money, will spend more percentage of their income that those who have huge wealth, so, more spending, the economy flows, therefore the economy grows, more money for taxes, more money for companies, bigger salaries, it is a wheel where the money which now is in tax havens or just in a bank deposit/investment, etc would flow through the system.