Your team will always sink to your lowest performers.
Nothing frustrates a high performer like seeing a low performer muddling through indefinitely.
The high performer either leaves to find exceptional peers, or they start questioning why they’ve been working so hard when this other person doesn’t.
And thus the bar becomes your low performer’s work.
The best thing you can do for high performers (especially kind, quiet ones who wouldn’t dream of complaining about their peers!) is to deal with low performers early on.