While it's possible that the circuit breaker is failing, it's highly unlikely. Generally speaking, if you're having an issue with a circuit, "failing/failed breaker" is the last thing you'd investigate.
It's probably just a bulb failing. Light Emitting Diodes (LEDs) themselves basically don't fail, but the electronics that drive them do. The cheaper the bulb/fixture, the sooner it will give up.
In your case, replace the flickering bulbs. It's possible that your fixtures have integrated bulbs that are not replaceable and you're looking at replacing the entire fixture. While that's significantly more work than unscrewing a dead bulb and screwing in a new one, it's not too bad.
It's generally recommended that you buy quality equipment to help prevent this from happening again. Cheap fixtures will tend to lead to cheap components and early failures, requiring another replacement. Also, do not purchase from online retailers (unless you're buying a known quality brand also available locally from your brick and mortar store), as there is a strong tendency for them to use various laws to enable them to pass along non-UL certified equipment.
Loose screw/wire nut connections are also a likely candidate, and it's never a bad thing to check connections. All newer fixtures and devices will have torque specs (in inch/pounds) that should be followed. Loose connections could manifest as flickering lights but could also manifest as a fire.
