You have to work if you want to get paid. Otherwise you will get fired. The obligation of the state is to provide you with a guaranteed alternative job offer, not a guaranteed income.

It’s up to you if you take up the state’s offer or not.

The UBI removes the motivation to work and turns everything into volunteering. The result is a rise in the “reservation wage gap” - the amount the private sector has to pay to get people to work for them.

The reservation wage gap with a job guarantee is near zero - which is more economically efficient.

Additionally the job guarantee acts as a powerful spend side automatic stabiliser that is temporal and spatially efficient - which removes the need to manipulate the base interest rate allowing it to return to its natural rate of zero. This allows permanent cheaper mortgages and business loans.