In a perfect world, Barca would get cut their losses and get rid of the deadwood. However, it's not a perfect world and Barca are doing a ridiculous balancing act of trying to cut their wage bill while trying to finance a move for Haaland.
So i suppose it makes sense from that perspective. But it just screams that Barca is getting some short-term benefits for longer-term costs.
I'm not particularly familiar with Umtiti's case, but is there any chance of him playing regularly again? If he can get back into the team, it's a gamble worth taking. Or at the very least, he can be sold to some other team. But worst case scenario, you're paying deadwood for the next five years.