Social care definitely needs sorting as it's been underfunded for ages, but NI in it's current form is the wrong way to fund it.
Someone earning £20k a year will now pay 6.9% of their salary on NI, going up to 10.7% at £50k - fair enough, but then it starts to go down, with £100k earners paying 7% and £130k earners 6.1%.
Income from share dividends, investments and property are exempt from NI too.
Should be income tax, not NI.