I agree that the numbers put about in media that "Subsidies within super to rich people costs the Australian tax-payer $xB" are never going to realise $xB as people will structure their investments differently.
But as
@33kft says the point is to discourage people sheltering more money into super above $3M rather than realising that money
With the DB benefit, let's say the valuation is 14x:
(a) Would you be comfortable drawing down an equivalent non-DB fund at 7% p.a and it lasting until your 80s?
(b) if you had a time-machine and could have opted for a non-DB fund knowing the tax-treatment would be as it is now, would you have made the switch?