Was this really possible back then?
As long as nothing went wrong, yes.
Job security was a big part of it. So long as you had a job, you had an income. And for most workers the only reason to leave a job was to get a better one, quite possibly with the same employer. And in the unlikely event that the employer did go broke, then it was fairly straightforward to get another secure, permanent job somewhere else.
You only have to go back a generation or so to find a time when most things that people owned were made in Australia. Furniture, white goods, TV's, cars, clothes, tools -
of course you bought Australian made. Sure, there were foreign goods around, but most things were made right here.
We have since gone down the track of trying to compete against countries with minimal standards for safety, environment etc and which pay wages an order of magnitude less than Australian rates of pay. It's a game we'll never win, the end result being that we've become reliant on selling rocks and borrowing money to keep the game going.
A current one which symbolises the change is at Burnie, Tas. The Pulp, which once employed 3500 people on high wages, is now just a pile of rubble being carted off to the tip. In its' place is to be a national chain hardware store which sells mostly imported goods and which might employ 100 or so on much lower wages than the Pulp provided. Sure, that factory had a downside in the form of very visible and undeniable pollution, but it actually made something of value, exported it and employed people by doing so. If it were still viable to manufacture in Australia, modern technology would have fixed the pollution, indeed there was considerable improvement in that regard happening in the latter years anyway. But it's gone now, all those jobs and those of suppliers and contractors with it, and it's not coming back.
There are countless stories like this right across Australia. Where once something was made locally, now there's either nothing or at best a warehouse distributing imported product on the site. Hundreds or thousands of stable, high wage jobs in each case replaced with a lesser volume of lower paid work with far less stability.
Against that backdrop, it's inevitable that continuing to inflate house prices will leave many "locked out" of the market. Aside from mining and a few select trades and professional services, the economy no longer is able to provide the types of employment for the masses that would sustain such growth in the long term. If the best you can get is a casual job on $20 an hour then you're not going to be buying anything resembling a decent house anytime soon.