For most consumers the accounting cost and effort will far outweigh any gains, given the small volume. You literally have to account for every single transaction, including hilariously tiny ones, and it's very complex to calculate the delta.

You need the date and time of disposal, the cost base (the AUD value you originally paid for that specific portion of BTC), the proceeds (the AUD value of whatever at the time of purchase), and the resultant capital gain or loss. Who on earth is going to put themselves through that hell if they don't have to?

Maybe down the line some fancy software will help, but only so much.

Also there's the question of why pay the capital gains now when you might not have to pay it later? Tax laws change, and if the current amount is high then a future amount will surely be lower.