They don’t.
For most people, PAYE income tax includes a Personal Allowance of £12,570. NI, which is income tax calculated differently would not be payable either on an income that low.
Current Job Seeker’s Allowance (Unemployment Benefit) is around a third of that.
Of course, the system is complicated and it is hard to quote generation, but unemployed people who don’t have another income will pay no tax at all.
As a retired person with a couple of pensions, I do pay tax and I am happy to do so.