Frankly, this is exactly the sort of head-up-ass attitude that will end with Apple being smacked around by investigatory commissions like what happened to John Deere and Microsoft.
My suspicion for their shitty process is that it was set up purely so Apple can tell regulators "see, consumers can't be trusted to replace their own batteries, look what it takes", but they do offer a programme for it.
The stupidest part about the whole thing is that the official URL looks like a total scam: https://selfservicerepair.com/en-US/home
Not only that, they won't repair devices with third-party hardware. If my Mini has an issue, I'll have to remove the new SSD and reinstall the OEM one before I drop it off. I experienced this when tried to get my 2012 MacBook Pro fixed (wet keyboard).
They did the replacement, but I learned how to do it myself, including replacing the keyboard again, another SSD upgrade, and eventually a battery upgrade.