It sounds like you made up your mind in advance to support this. Mozilla (and I believe Google too) have a public and rigorous process to determine which certificates to include in their browser, and, importantly, which not too. This new regulation would enable governments to circumvent that process and force browsers to include their certificates, even if those are used to spy on citizens, or are insecure - like the government of Kazakhstan tried to do before. All this using a process without checks and balances.

Also note that parties like Google aren't trusted "exclusively" - you can always switch browsers if you don't trust them. That will no longer be possible with this regulation.