That's not the most profitable that the biggest return on investmentI'm not really sure. There's a lot of unknowns.
Supposedly between actors taking a cut, China and the $500 million production and P&A budget, Endgame's profit for the studio was closer to $500m.
Which is about where Joker is now in terms of profit due to low P&A and production budget.
Although who knows how the numbers actually turn out. I would imagine only Disney and WB know their numbers and they probably wouldn't want to share it.