People will have to work if there is no pension for them to have. Thankfully many 74 year olds will be able, physically, to work full time in different sectors. It’s shit they’ll have too, but if there’s no pension they’ll have no choice
Many 74 year olds won't be fit enough, so they will end up claiming disability benefits, so no saving there.
This change will only happen if we the electorate allow it to. That entails getting wise to this government's tactic of turning young against old, blaming immigration etc etc.
As pp have said. we already have one of the highest state pension ages in Europe. Other countries are creeping up to 67 and 68, but none have anything higher.