For full transparency, I lived in the UK for most of childhood, but I moved after school and have never bought property there.
I have however bought in Australia. It's very straightforward (though horrendously expensive). You offer privately, or buy at auction. To seal the deal, you put down a 5-10% non refundable deposit, and 6 weeks later you exchange. If you pull out for any reason, you lose your deposit. There is no such thing as a chain here - if people have nowhere to move to they move in with family, rent short term etc.
I was talking to my cousin who is selling and buying in England at the minute. It's been a nightmare with 2 collapsed chains and has been ongoing for almost a year now. She is tearing her hair out and has vowed never to move again when this is all over.
Why is it so complicated in the UK? Why do chains exist? What is the advantage to them? How can other countries manage without them and yet the UK does not? It sounds ever so stressful to have it set up this way.