Google is going Apple and hiding IP addresses.

The feature is called IP Protection (formerly Gnatcatcher, which sounds cooler, tbh), and it will limit IP tracking by third parties.

This “could mean that the IP address is not the viable post-cookie alternative some thought it might be.”

I don’t know why it was ever considered a viable alternative in the current privacy environment. Part of the reason GA4 dropped IP addresses was to conform with privacy regulations.

3rd party IP access is going the way of 3rd party cookies, not replacing them.