Ironically, NIC and state pension rules are pretty good for low earners as they can accumulate "credits" for state pension etc without paying any NIC if they earn below the thresholds.
I've quite a few clients who were low paid (mostly part timers) for most of their life, and actually have higher pension incomes than their average wages (adjusted for inflation etc) because of these rules for accumulating credits. Some basically got a "pay rise" the moment they retired, who'd previously worked part time (earning under state pension amounts) but then got full state pension. The position is even better for those, like part time NHS/school workers who also get a final salary public sector pension scheme and state pension.