This is dismissive and incorrect. iFixIt, the authors of this piece, provide everything someone needs to do such a replacement: tools, parts, and in-depth user guides. I've replaced an older-generation MacBook's battery using their stuff, and it worked fine. What more do you want?
It's similar for most older laptops too. I have a few older HP laptops, and on every one the battery just slides out if you pull it hard enough - no screws at all.
The vast majority of people are not comfortable opening their computer and mucking around the guts. In the old days Apple made this simple for their users:
Coming from a x220, x230 thinkpad, removing anything at all or needing to use a screwdriver at all is way above what most are capable of doing. Obviously what I am willing to do to fix my spouses iphone, and what the average person is willing to do to self - replace are very different.