Ehh that's a very cynical and kinda misleading take of how it works. This may be generally true in the house of representatives but still 12% of the seats don't end up funnelled to the two major parties. In the senate a quarter of senators aren't affiliated with either major party and at the moment it requires Labor to collaborate to pass bills, so although we do have two major parties we are nowhere near being a two-party system.
Can't mentally decline if you were never sound of mind in the first place!