Here is info on stylus life!
HOW LONG SHOULD A STYLUS LAST?
A worn stylus damages records, causes distortion, and affects tonal response. What, then, is the life of a phonograph stylus, and when should it be replaced? The first part of this question is rather difficult to answer with any degree of exactitude. Asking, "how long should a phonograph stylus last?" is like asking "what is the life of an automobile tire?" To answer such a question, even approximately, would require additional information, such as: the weight of the car; the speed at which it is usually operated; the type of roads over which it will travel; whether gravel, dirt, or asphalt; the quality of the tire itself, etc. Quite a number of variable factors! The life of a pickup stylus depends upon at least as many variables. Among the factors influencing stylus wear are the material of which the stylus tip is made; the condition of the records with which it is used; and the stylus pressure. Also of considerable importance is the ability of the pickup itself to follow the impressions engraved upon the groove walls with the least resistance to the motion they cause. This is called "trackability" and is related to a specification called "compliance."
The second part of the question, "when should a stylus be replaced?" is not quite as difficult to answer, though the answer can only be an approximation. As a rule of thumb, a diamond stylus should be replaced after 800 to 1,000 hours of playing time.
And more!
https://www.gcaudio.com/tips-tricks/how-long-will-my-stylus-last/