You mean the crypto shit you can disable in a couple of clicks and completely ignore? Firefox doesn’t have that good of defaults either. You also have disable things like Pocket and change some settings to make it good. It’s why Hardened Firefox and Librewolf exist.
And where did I say that open source = good? I just said it being open source makes it easily to see if they are doing something shady. It’s how they were caught changing the referral URLs a few years ago. If they try to pull anything they would be caught the same way they were before.