It will make it extremely risky from a liability standpoint to operate any platform that allows user content.

The EFF has a bunch of writeups on these types of laws. This is the last of a 4-part series on them: Link

Fediverse operators would for example be extremely vulnerable to lawsuits, because almost none of them can afford teams of lawyers to deal with claims, true or not, that they failed to enforce content policies.

Depending on how the laws are written, anyone who could find a piece of objectionable content (which will vary by jurisdiction) could sue the platforms. This makes it very appealing as a route to shut down platforms you dislike, especially if they're niche.

It consolidates power under large corporations like Meta and Xitter, who can afford to handle legal threats.

Consider a Brazilian Lemmy instance. They will have to remove everything anyone complains about.

There's no way to tell legitimate requests from illegitimate and as soon as volunteer admins are overwhelmed with requests, they will have to automatically delete any post that they are notified about.

All the power is on the side of the complainant. Nonprofit Lemmy hosts would go bankrupt in minutes trying to fight it.

It works only for big tech. Small forums, for example, often can't comply with such regulations.

I just don't see how smaller social groups like forums or fedi stuff can survive if they need to potentially fight legal battles too.