I don’t see how. User replaceable batteries require extra protection around the battery and extra volume for the mechanisms required for taking it in and out.

I don’t see how. User replaceable batteries require extra protection around the battery and extra volume for the mechanisms required for taking it in and out. They’ll never get the difference in lifespan and charge capacity to go to zero, but it might be able to get it low enough that a few more years of hardware improvements will cancel out the difference.