This year?
There may be a case for this perception at a time when there were shortages down under and active recruitment campaigns in the UK. Going through an agency, whether from, say, Malawi to the UK, or from the UK to Australia takes a lot of the leg work out of the process and agencies will have built up longer term relationships with hospital recruitment staff than individuals and offer practical support (CVs, interview technique) and mentoring. (There is resentment in the UK about strong relationships overseas agencies have with individual hospitals leaving local staff feeling they don't get a look in.)
One reason why UK doctors looking for work in the UK are on the back foot is that despite it being so competitive they don't receive targeted careers advice/support that would help them deliver polished applications. If they were at University they would have access to a University careers department.
Instead DD is working nights, often staying late because the consultant is late carrying out the ward round or she has not had time to complete handover notes. At best she might find time to scribble off an application before getting some sleep, but the odds are so long it is hardly worth it. At the moment her job has to be her priority. It was always going to be busy. They are 3 F2s down out of six and work involves travelling to smaller hospitals across a wide rural area. She spent a couple of weekends before starting batch cooking so she could save time. Great for learning and experience. Unfortunately of no help in career terms.
Australia etc must now be flooded with applications and will know they won't need to make any effort. DD was getting recommendations for places to apply to from senior colleagues who had previously worked in Australia. Even with personal contacts she got nowhere. Vacancies had been filled. If she can't get enough NHS bank work where she is, she will apply again, this time using an agency and fully aware that despite a strong CV and good references it might not be the speciality she wants, and that she won't get to choose where she goes.