You keep them because they are "nice". Or "trying hard". But they are missing targets. The rest of the team is fixing their bugs. Principle: What you tolerate, you encourage. If you tolerate mediocrity, you will lose your stars.

Do not sandwich the bad news. "You're great, but you're fired, but we love you." -> Confusing.

The Script: "John, I have bad news. Today is your last day at Mentasm." State it clearly in the first sentence. "We made this decision because [Data-backed Reason]. This is final."

1. Be Generous: severance, references (if appropriate), help them find the next role.
2. Be Honest with the Team: "John is no longer with us. We value X, Y, Z."
3. Do Not Trash Talk: Protect their dignity.

Firing is not an act of cruelty. Keeping someone in a role they are failing at is cruel.