"The society" is a generic term to hide behind; the society does not provide jobs, businesses do (or self-employment). Nobody provides a "dignified life", that is another vague and non-measurable term to hide behind.

problem with your utopia is that in order to provide the vagaries of a "dignified life" you are compelling people to labor for others. We have not yet achieved post scarcity and there is never a guarantee that enough people in your society will participate in good faith to sustain those who are, for whatever reason, less productive.

That's not an argument against a safety net, just the opposing force that makes the correct (and possible) solution somewhere in between [UBI, euthanization), and different for each grouping of people.