And you can do it for much less if you want. I've replaced phone batteries with 6 dollars worth of tools and a hairdryer. You can buy glue or sticky gaskets for next to nothing as well if you care about waterproofing.

Most people are going to give up in 1 minute trying to open a smartphone. I can't imagine most people I know succeeding to replace the battery by themselves.

Most people I know would come to me to replace the battery in an old Thinkpad, and those were made to be easily removable!