but that might not be the case. The thing about laptops is, with battery backup if there is ever a mains power cut, the battery takes over immediately and you don't lose your work, or cause other problems with an unexpected shutdown.
So my own advice is, get a replacement battery as soon as possible. Since the incidences of laptop batteries catching fire some years ago when cheap replacement batteries were being used, the recommendation is to get batteries approved by the maker only, and not cheap 3rd party batteries. They may not be safe.
Why would you want to get a new laptop if this one is working well otherwise? Only you can decide that.