just design and sell 2 games at once

The solution for the major community discords is simple to design 2 games:

-a more relaxed, farming hordes of monsters focused poe 2 with lots of loot drops, playing similiar to PoE 1 and also attracting parts of the diablo 4 audience

and

-a challenging, tactical action rpg with souls like boss encounters and consistently increasing difficulty curve, playing similiar to nothing that ever existed, because its a genre innovation that is already positively resonant enough for many people to argue even though its only half-implemented yet

The community arguing so much about certain topics means you've attracted two different audiences. Congratulation, you can sell your game to both of them, using the same monsters, the same campaign, same sound effects...
The only thing you need to do, is to consciously design it for both of them and clear communication that you'll support them without going for a compromise, but creating seperate gameplay spaces for both of them. Just let the player customize their own experience like level of challenge, monster density and create 2 actually different feeling gameplay experiences.

It's important that you design mechanics, balance and gameplay for both modes.

There could be an easy mode campaign that is even easier than the current one. One would always find enough resistances on gear, there is plenty loot and act bosses are easier, so players can pass them.

There could be a hard mode campaign where players encounter a grim and challenging world once they step outside clearfell, loot is scarce and players need to intentionally decide on which items to invest upgrade materials and bosses need to be practiced until their patterns are learned. As reward for the increased challenge you could end up in early T14 maps gear wise at the end of the campaign.

No compromise, no "if the game is more like that, its better for me, but worse for you", but 2 seperate difficulty levels from the ground up designed for their target audience.

And endgame could be similiar to this: In one mode one has to pay attention to what the monsters are doing and respond distinctly: if I hit a monster with a damage reflection ability activated, don't play around it and don't react soon enough, I die. In the other mode, such effects would be much less impactful. They still happen visually, but I can make mistakes often, drink a health potion now and then and be just fine. One can have a relaxed evening of farming without stress.

Once the initial work effort is done - which might take a year, they game should become more profiteable than it can otherwise become.

Why would they do that? That's crazy talk. Two different games to appeal to different players?

It's so much better to have their primary team focusing on the older PoE, and then have a smaller team slowly porting old game play elements from that game to the newer game while promising it will be different and better.