

Yeah all you have to do is circumvent the security settings in your browser and suppress warning messages to enable Manifest 2, all in 8 easy steps (written as if it’s 6 steps to make it seem less onerous). For now. Until Google switches it off completely.
Or, drop Chrome and Chromium based browsers (such as Edge, Vivaldi, Brave etc) in one easy step. Install a privacy respecting Firefox based browser like Firefox itself or Librewolf.
That link is for Piefed.world; run by the same team that run Lemmy.world
There are other piefed servers which may have different email requirements. But the most likely reason Piefed.world requires real emails is to prevent bots making fake accounts and also reduce the risk of bad actors making numerous accounts to avoid bans. As it’s hard to get multiple real emails it makes it hard to make multiple anonymous accounts which is unfortunately a tactic of trolls.
You can of course create a dedicated “private” email account on an official service and use that to sign up if you’re worried about sharing your primary email account. A lot of people do this online to have a legitimate email but essentially in it’s own silo separate from other personal emails.