In Australia, there are equal and proper rules for the car owners and the bike owners that govern their activities on the road. Due to the fact when they are on the road they are at risk of getting into trouble either people are riding on the bike or they are on their car.
In case if one person gets into any kind of accident due to the fact the other one is at fault, there is a definite need to have an insurance or coverage that may compensate the loss either for both of them or there should be third-party insurance covering all the expenses that are there for repairing or compensating the damages done to the other vehicles.
In most cases, the bike insurance or the motorcycle insurance cover the damages done to the third party damages because if the motorbike owner only has the CTP then it will only be covering the damages done to the vehicle or the property of the third party and not you.
Though it is still beneficial for the insurer because they will not have to pay for the damages.
In case if you need to make sure that you will also get enough compensation for your own loss then you may ask for or find an insurance that covers you as well.
You may get the insurance for the driver at fault so that your loss may also be compensated so that you as the insured person gets the relief as well. But in fact, having the compulsory third party insurance may help a lot and get things easier for you to manage because you will not have to pay anything for the third party and the insurance company will compensate it for you when claimed.
It is also important because the government has a legal requirement for the vehicle owners to have the CTP to drive on the road.