It's absolutely about NIMBYs, but I wouldn't blame "NIMBY politicians" as they are responding to the demands of their voters (else they fairly soon wouldn't be politicians).

An interesting article about the UK has never really built houses, except for a very short time before the second world war: https://worksinprogress.co/issue/why-britain-doesnt-build If we haven't built sufficient houses for this long it's hard to see what could change to allow us to build more.