Why do the over-60s pay no national insurance, however much they earn? Abolishing that would bring in £3bn, and that is enough to repair the shaming state of care.
Because national insurance is just that, insurance.
Once you’ve paid the premium you’ve paid the premium.
If you want to abolish that link, then fine (as the new pension for everyone will do). At which point you stop having national insurance and simply fold it into income tax.