Ask any manager after letting someone go the following question:
Did you fire them too late or too quickly?
100% of the managers will say they waited too long.
Wait. What gives? We all knew the employee wasn't a fit and we did nothing for months?
The reality is most managers, especially new ones, see firing someone as a hurtful thing so we are slow to do it. You're obviously impacting the employee's livelihood, family, self-confidence and potentially their reputation. It's clearly a short-term negative.
Long-term, it's different. Letting someone go is actually enabling them to go out and find a role where they can thrive sooner rather than later.
And when you see someone who is thriving in their role, doing what they are put on the earth to excel at – well, that's just a magical thing that everyone deserves and you're doing the hard thing to help get them there.
If it's not working out, clearly the role you have is not a good fit for them. You know it. The employee knows it. Their coworkers know it.
(Spoiler alert: by the time the boss knows someone isn't a fit, their coworkers have known for months!)
You can take solace that you're helping someone – and it's not all hurt when it's time to separate from an employee – and maybe move faster next time around.