It's a race to the bottom for providers, everyone's margin gets squeezed to compete, and services suffer as a result.
So you can buy a $69 hop from BNE to SYD, but there's no guarantee on timeliness, no practical refunds, and you will be provided the bare minimum of comfort and facilities on your trip.
If I have to stay in a cheap hotel in Tullamarine so I don’t miss my flight, I arrive stressed, tired, hungry and usually late for my appointment.
If I catch the XPT from Southern Cross, I arrive refreshed, relaxed and satiated. I can then take advantage of Sydney’s public transport to get to my appointment on time.