So when there used to be free eyetests and prescriptions and indeed no student fees across the UK, someone else was paying for it?
As to means testing , it's often innefficient and discourages take up amongst those who need it most.
No.
We were paying for it.
We stopped doing those things because, in the opinion of the governments of the time
we couldn't afford to pay for them.
If Scotland had to cover the costs of free higher education etc out of taxes that it raised rather than out of general UK taxation, there might be a bit more pressure to stop providing them for free.
Your argument about means testing is utterly facile. If it were serious, there would be no means testing.
ETA: Yes I broke my promise not to comment again. Maybe a moderator could split this line into a different thread.