For instance, I would consider it a much bigger privacy violation for my phone to transmit my exact location every hour than my current CPU usage every 10 seconds.
https://support.apple.com/en-us/HT203033
They do send nearly WiFi hotspots for crowd sourcing purposes but it is never in conjunction with your local IP address (which is an identifying piece of information).
Apple does not explicitly "send" the user's IP address. It naturally is accessible on their end as a result of the TCP/IP protocol. But Apple has made quite clear that it does not use that information in any way.