I agree housing affordability is a multi-factorial problem.
BUT
Immigration is a very important driver of the demand side for housing. The projections was that Australia would reach 28 million in 2051. It happened in 2026. Most of it by immigration.
That's important because the sharp increase in population was not taken into account in government policies around land release, infrastructure eg schools, roads, health and ageing support. The projection was we wouldn't need to that until 2051.
The other major factor is the monetary policy.
Former RBA chief Phillip Lowe should go down in history the most incompetent ever. He held rates far too low for too long at a time when the government was throwing money at everyone and everything.
He then reacted too late and went too hard when he finally saw what he had done, lighting a bonfire under inflation which was obvious to a first year economics student but not him, ScoMO and Albo. His and the government's monetary policies are not only a major driver of house prices, but also inflation, and reduced private sector jobs growth and productivity.
The CGT concessions and NG are relatively minor in the scheme of it all, IMO, maybe 5% if that. That's just politics of envy and division that modern Labor relies on to win elections.