One of the most common issues I've come across as an HR Manager is exceptional candidates leaving in their first year, much to the lament of their managers. I've been there myself, both as the hiring manager and the leaving party. During exit interviews, a common theme emerges; the role is not what was sold to the candidate during the recruitment process.
Employers, rightly, want to put their best foot forward. They want candidates to think they're joining a fantastic organisation and that their role will be rewarding and fulfilling. They'll bulk at highlighting issues, in part because you don't have much control over the messaging of an unsuccessful candidate who might be feeling a little rebuked, but also because they don't want to lose a fantastic candidate.
Some time ago, after taking this exact same approach in my own hiring, I switched up my recruitment process to one of radical transparency. Sometimes not complete transparency – obviously reputational or commercial in confidence matters come into play, especially in instances where you're working in a small industry. But pretty close to. I train managers to do the same. We talk about not only what is great about the organisation and role people are applying to, but also the problems. We tell them why the problems exist and why they have been hard to resolve. It has resulted in some pretty full-on interviews where really solid people were asked how they would deal with really complex issues and came up wanting.
But a) they were the issues the hiring manager or I needed them to pick up and solve, and b) I'd rather know at interview that they don't want or can't resolve them than seven months in when the proverbial hits the fan and probation has passed. But also, we want them to hang around – we want them to want to solve these problems. So far it has never failed me.
There is a great sell in this approach (as long as you don't present it as 'this place is a disaster'). What are two of the greatest motivators for people in their work? Meaning and knowing your work is contributing something. The successful candidate gets to solve problems the organisation needs resolving. It's a chance for challenge and genuine achievement. It demonstrates the organisation is humble, open to its own failings and to being helped to fix them.
Of course, you have to tell people what is great about what you do too, but it's much more powerful to give them the whole picture. And you're much less likely to be having to fill the role again six months later.