There is a reason that nobody filters by social first.
One of the biggest challenges in hiring is that it takes a ton of time to go through many bad candidates before you see any good ones. And time is the one thing you don't have. You're hiring because you don't have enough resources to do the work you already have.
Therefore the name of the game is efficiently rejecting candidates while using up the least amount of your existing people's time. Which means that the most expensive filters should be done last. And the most expensive one is social because judging it takes time from EVERYONE.
And that seems fair.
Why is it only the employee that is expected to take up time? At the end of the day there is likely to be more than one applicant, so your spending 3 hours of your time for 50% chance at best.
The fundamental reason why this is OK is that the company is hoping to pay hundreds of thousands of dollars for the candidate's time. The person who pays the piper, gets to choose how it happens.
But that said, it is still fair. The effort required to hire a new person into a competent company is significantly greater than the effort it takes a competent person to get a new job. As a candidate it doesn't look like this because you see that you personally gave the company more attention than vice versa. However you don't see all of the other people who the company also paid attention to and ultimately rejected.
If you're a competent developer it probably still doesn't look like this because the company usually develops procedures that concentrate the required effort in the hiring manager and/or HR. Therefore you have little idea how much effort is actually spent looking for candidates.
But spend time as a hiring manager and it will be obvious.
One of the biggest challenges in hiring is that it takes a ton of time to go through many bad candidates before you see any good ones. And time is the one thing you don't have. You're hiring because you don't have enough resources to do the work you already have.
Therefore the name of the game is efficiently rejecting candidates while using up the least amount of your existing people's time. Which means that the most expensive filters should be done last. And the most expensive one is social because judging it takes time from EVERYONE.