I can’t backup my claims about their service so you’re right to call them out, but as you can see the kit is not only cheaper, but has plenty of good reviews as well as a two year warranty.
I don’t know wether you distrust all aftermarket parts or just batteries, but I have no doubt it’s because you’re familiar with battery horror stories about exploding or catching fire. I assure you if this was common, amazon would not sell them. Not to mention, I’ve only ever heard of batteries exploding that came with the device at purchase. For instance, the galaxy fiasco.
This is why we need Right to Repair. I shouldn’t be forced to pay 50-60 USD to replace a battery when I can do so myself for 19 USD.