... which they do! It's $69.00 for the iPhone 13 mini battery or $70.99 for the kit which also includes a replacement display adhesive and a set of spare security screws. In both cases, you can get $24.15 credit when you return your old battery.
You don't have to get the toolkit; you can put together your own tools and do whatever crazy shit you want with a hairdryer or whatever.
Are you seriously saying that Apple's decision to both sell and rent (on what I'm pretty sure must be a loss-making basis) the tools that they themselves use for the repairs is ... malicious?