There are too many ways a battery winds down. The worst is if it loses a cell and that cell shorts out. This causes a condition where the battery can be constantly charging and could overtax the motherboard battery circuits. I can't guess if you know the other failures.
Another failure is loss of capacity without the deleterious effect noted above. That battery I don't have any problem with leaving it in.
If the battery just flat out holds no charge and won't charge and doesn't warm up due to charge attempts I might leave it in.
No, no one is forcing you to replace it. But you may have to research all those failures.
Bob
Hi
My Inspiron battery is coming to the end of its life. I'm happy to just use mains, can I leave the battery to die or remove or battery or must I purchase a replacement.

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