Apple is the largest company in the world so no, their “indignation” over having a competitor is never justified.

You are also assuming that only Google benefited from that relationship which is wrong.

Google is a software and services company and in an iPhone world Apple would decide how and when these services are presented to users, if they are presented at all. That is an unacceptable amount of risk as Apple had a disproportionate amount of leverage in that arrangement.