"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.
we seem to have enough people participating to sustain large scale warfare operations around the globe, bail out entire industries, and pay politicians above average salaries. imagine what we could do for society if not for spending so much money on these pursuits which large swaths of our population find immoral.