When you look at Sussan Ley’s predicament, you can’t help thinking of Brendan Nelson.
Nelson, a Liberal moderate and a former minister who was a competent but not outstanding performer, won the Liberal leadership after the 2007 defeat of the Howard government. He then never had a chance. Malcolm Turnbull was determined to bring him down (only himself to be ousted by Tony Abbott before the 2010 election, which the Coalition narrowly lost).
Ley came to the leadership in worse circumstances than Nelson. The Liberals, already in opposition, suffered such a devastating defeat in May that it would be near impossible for any leader to be competitive at the 2028 election.