Australia, where did it all go wrong?

Since 2012, Australian cricket have found themselves struggling in Test cricket both home and away. Being whitewashed in Sri Lanka (2016) and in India in 2012/13, two series losses in the Ashes away to England Series, defeats to Pakistan in the UAE (2014/15) rank as just some of the lowlights. With only a series against India at home (2014/15) plus wins against New Zealand and the West Indies in that time, it’s a dark time for Australia. Now, they find themselves being 2-0 down at home to South Africa with the third Test having just got underway. Why is this the case for one of the cricketing giants?
Full disclaimer: I bowl slow left arm spin and bat at ninth man or lower, so I am no expert at seam bowling or batting. My comments throughout are just what I have seen and heard from watching cricket over the years.
The first point that springs to mind when thinking about Australian cricket is how they play against swing bowling. The answer? Very badly.
When trying to get the ball to swing, bowlers need to bowl fuller up the wicket, but not too full to allow the ball time to swing. England’s James Anderson is the master of swing bowling, especially at home. This is because the conditions help him, as it’s more likely to be overcast and the wicket has a little bit more grass on it, which helps. These conditions are vastly different to those in Australia. Australian home tests are played on hard pitches that offer little for medium paced bowlers if they bowl full. As a result, Australia’s bowlers bowl fast and pitch it short meaning the ball comes up around the batsmen’s head. Many people describe an Australian wicket as a road, and with good reason.
They utilise this to their advantage and, because they are used to this, they can score well from this. So when Australia tour England, they play in conditions their senior players don’t often play in. Coupled with the fact that the younger players would never have faced these conditions, it is a recipe for disaster. One such example of this was Trent Bridge, Nottingham, in 2015. Australia open the batting and are bowled out for 60 in just over 90mins. So, in summary, Australia struggle against top quality swing bowling in conditions that do not suit them.
This does not explain how they have lost series 2-0 to Pakistan, 3-0 to Sri Lanka and 4-0 to India in recent years. The principle is the same here. However, in the subcontinent, spin is king.
Australian pitches offer little in the way of spin. A lack of a quality second spinner behind Nathan Lyon means he is under great pressure to get all the wickets, which means these teams see him out and focus on the seam bowlers or the second spinners. The young batsmen in the South Asian countries have to learn how to play the turning ball, or else they won’t get near the professional game. Australian batsmen are always going to struggle against the quality of spin these countries have.
To be fair to the Aussies, everyone struggles in India just now. The Indian team is just that good. It’s at home that they should be concerned. After losing this most recent series to South Africa, signs are worrying. The second test was just embarrassing; all out for 85 in the first innings, and imploding during the second innings, going from 129-2 to 161 all out in less than 20 overs.
Australia are struggling in Test cricket right now. Something needs to change.

Thoughts? Opinions? Stipulations?