Pensioners often use Cash ISAs for money they are taking out of their pension or other vehicles like S&S ISA. It isn't that they are saving new money.
The LISA does have a limit which they should address, and it is likely to be replaced soon anyway. I understand there is a review planned and Martin Lewisis campaigning on the limit of house price and the withdrawal penalties.
However if someone has enough funds that they are putting away more than £12k a year and don't want to use the LISA because they are likely to buy a house worth more than £450k then they are probably savvy enough to explore other options such as low risk funds in a S&S ISA , premium bonds, or just paying tax.
These people may not be hugely wealthy but they are privileged and could reasonably be expected to pay a tiny bit more tax.
I use ISAs and am under 65 so I am not coming at this as someone unaffected.
I also have a LISA but the money is now effectively trapped until retirement or subject to penalties as I can't use it for a house purchase.