I have a 3.5 year old Teclast 98 Pro and is used daily. The factory battery half a year ago had 6000 mAh instead of 8000 mAh. Nothing happens with the tablet, bluetooth works, wifi works, lan works. Only Windows 10 is problematic because eg bluetooth will not work wirelessly with some hardware and windows 8.1 will work. I The drivers can break the hardware from the update of windows 10. And my winter in the battery lasts 5-6 hours and in the summer up to 8 hours.
90% of laptop, tablet or mini laptops have problems with batteries independent of the manufacturer. Apple is a single-use device that you do not replace batteries without damaging, for example, the screen.