The park cc-1, one of their finest tools
Tells you how worn the chain is.
It goes way beyond.
You can then use this information along with the user's experience and an estimation of their output to see whether anything needs replacing and how soon.
It needs experience and judgement to get the most from it.
Its replacement, the cc-2
Just tells you when you've reached a predetermined level of wear.
If mechanics trust this tool, they end up replacing almost every chain on working bikes!
From a mechanics perspective, it makes perfect sense, but from an economic or environmental perspective, it's verging on criminal!
The Bean-Counter's choice