At Amazon, perhaps one of the largest and most successful employers, the solution to this is that when interviewing, everyone's main goal is to hire people better than the current average of the team.

To ensure this, someone experienced with interviewing from outside the team/organization, so called bar raiser, is always added to the interviewing team. This person is there to ensure high quality hires and has hiring veto power.

The rest of the interviewers are from within the team, likely under pressure to compromise on quality when they're desperate enough to hire someone, but they can't do it unless the bar raiser agreed.