I think it all depends on each indivuduals needs if staying on the scheme is still beneficial or not.
If you do low miles and dont require little or no adaptions then leasing or PCP could be the better option.
As for second hand well its a lottery you can buy a £500 banger and have no trouble or spend £10k and get a dog.
The trouble in general at the moment is the lack of avialabilty be it through mobility, buying new or over inflated secondhand values.
One can only hope that things begin to improve.