Hiring managers and HR area increasingly only open to unicorn candidates that have the exact amount of experience in the exact tech stack. While a few of those people exist, it's definitely more likely they end up interviewing people that are open to lying. So now your pipeline is filled with 90% liars, some just small white lies and others who have made a resume that has exclusively tailored lies just for your org.

The jobs aren't that hard and many people that fudged their experience are capable, so the liars that are hired perform adequately and hiring team sees no reason to adjust their strategy.

Eventually this gets out-of-hand as people learn to further exploit these practices.