Sorry if I am boring folk and repeating myself (and stating the obvious) but there may be some who might benefit from a simplified explanation of the mechanics involved.
Many will understand how a clutch uses a friction plate to gradually transfer engine revs to forward motion so its not done too abruptly,stalling the engine. In time the friction material (similar to brake pads) can wear out . New clutch required. Simples
The release bearing is less well known. Basically the clutch us normally tightly clamped together by a powerful spring. The whole assembly rotates with the engine. To release the friction disc so it freewheels independently of the engine and able to do its magic, the pressure spring has to be compressed. Problem is the spring is rotating at engine speed, and the clutch pedal is not. For a static part to press on a rotating part some sort of bearing is required. (like wheel bearings)
This bearing may need to be a fairly slim line design and cant have too much grease ,which could melt and contaminate the clutch. And a lot of force is needed to compress the spring. It has a hard life.
Used correctly it should last as long as the clutch linings. Its normal practice to replace the clutch release bearing at the same time as the clutch even if it still appears ok. But on some cars it can get noisy before this , even when used correctly.
Normally it only needs to compress the spring for a second or so until you are in neutral and release it. If you sit with the clutch pedal depressed for say 10 seconds its under stress for 10 times as long as it was designed for . Equivalent of a 11K mile car having done 110K miles.
Or more precisely a 110K mile release bearing with a clutch that has only done 11K miles miles.
If it is the clutch release bearing (and it might not be ) it will probably be ok for as long as the noise remains tolerable . Ideally get an on- the- spot opinion from an experienced mechanic who is honest enough not to suggest unnecessary work.