Whether or not you have a 'right to privacy' does not mean Zoom has to provide it. You can choose a provider who allows you to exercise that right.
“Free users for sure we don’t want to give that because we also want to work together with FBI, with local law enforcement in case some people use Zoom for a bad purpose,”
So they want to keep the data unencrypted so they can give it to the feds. That doesn't sound like privacy to me.
edit: So I mean, something like that should not be allowed by law. Though it's rather the FBI that is breaking the law here, but Zoom explicitly says they want to work together with them. So that means they approve that injustice, making them also unjust. If they would encrypt their data to protect their user's privacy, they would not be unjust on this aspect.
A hotel that suspects you're taping child porn in one of its rooms is well within its rights to call the police. If Zoom has reason to believe you're distributing child porn in a Zoom room, why shouldn't it be allowed to take action, too?
The point of encryption is that no one knows what you're doing, because they can't see it. Just like no one can see what you're doing in a hotel, most of the time.
So they can't literally see you every moment, but they have a lot of visibility into what you're up to.