It takes about five seconds after a new phone is released for Chinese factories to design and start selling all sorts of accessories, including batteries. High quality ones too.
The average consumer needs to be able to swap it without doing deep surgery on the phone, and that's on the phone's manufacturer.
The same factories that made the current battery that is a fire risk. yes. or maybe different ones, with no vetting for how dangerous their batteries are.
Yes, in all likelihood the same factories. Which still make your choices a battery that needs replacing but can't be without voiding your warranty, or a battery that needs replacing that you can swap out easily. Am I missing something?
Because a deep-pocketed company can be sued to recover the cost of my house - Samsung, Google, or Apple, and they take all possible precautions to make sure this isn't needed. Not going to successfully sue "big luck bright shine battery company of shenzhen"
The average consumer needs to be able to swap it without doing deep surgery on the phone, and that's on the phone's manufacturer.