> so that there is still an incentive to contribute to society with your work.
I think you're mistaken on some parts. The problem that UBI is trying to solve is that we're quickly approaching a situation where we don't need people to 'contribute to society with their work' anymore.
On some basic level the economy works because companies produce products and services and the consumer pays for those products and services.
Currently the consumer side is in large part financed by wages.
This means that a large part of the economy is dependent on a large part of the consumers being employed.
This will be a problem when there is a very high possibility of mass unemployment when advances in AI will make most jobs obsolete.
The solution is to decouple the consumer income from employment, through something like UBI. This allows people that are jobless to still contribute to the economy and keep (local) businesses alive.
For this to work UBI actually does need to be able to provide a comfortable (desirable) life. This doesn't mean luxury, but it should allow someone to have a house, buy groceries, visit friends and family, use (public) transport, go on a 2 week (national) vacation every year, save a little bit.
If the UBI is not enough to provide a comfortable life, people will still need to work which doesn't solve the problem.
I think making the UBI low enough that most people will still work is exactly what would cause inflation. If the UBI replaces wage, the amount of money in circulation wouldn't change, so no inflationary pressure. If people keep working but get an extra UBI on top, the amount of currency would greatly increase thus lead to inflation.
Personally I think we all should just accept that if we allow people to truly choose what they want to do, some of them will choose to do nothing. But in general people are productive creatures, and most if not all, have some limit to the time they don't want to do anything. Besides that UBI would be a great incentive for people to start their own business, volunteering, or doing valuable things that are inherently unprofitable