No such tools, and Im not sure what might help in that regard.

Lemmy and the Fediverse are fundamentally different platforms, so I doubt that it will devolve in that direction. Reddit as a for-profit company makes money from ads, so all they care about is "engagement" which increases when people get angry. Lemmy on the other hand is run by volunteers who will not tolerate that. These volunteers have the power to ban or block toxic actors and I expect that they will make use of that power (see beehaw). Its more likely that there will be multiple parts of Lemmy with different levels of toxicity which are loosely connected. Then users can choose if they rather want a harshly moderated instance like beehaw, something loosely moderated or anything in between.