Dunno about done like, he's 24. Most CBs peak at their late 20s. I still have some hope that he might make a decent CB one day. But I agree with you in that he's running out of time convincing that he's Man Utd quality and is worth persevering with. He's entering his 3rd year at the club now and he's still showing fundamental flaws to his game that prevent him from nailing a spot.
He's rash with his challenges, he gets drawn out of position a lot, he hacks and ninja kicks at the ball and botches his clearances (he scored an OG against Liverpool with one of these last season), he's poor in the air. That's a terrible array of flaws to still have at 24.
The fast he's quick, strong, agile and is often good in the tackle (all to his credit) does not erase these major flaws. It's speaks volumes that you simply can't rely on him to be an assured and calm presence at the back which is what you need first and foremost. It's the opposite, he creates panic. People call him mad and have a laugh, like it's a compliment. He's a fecking CB, not an MMA fighter.
I'm starting to see some positives on Lindelof at least. He's more calm both in possession and without the ball. His clearances are mostly good and he doesn't tackle unnecessarily. He's disciplined in his positioning and doesn't get drawn out everywhere. He needs to improve his alertness and tracking of runners and he needs to hit the gym and gain some strength. He's still quite rough for a 24 year old, but at least I see some good positives in him. Might be worth pairing with Smalling for a while and see how it goes.
Bailly and Lindelof pairing as some sort of ball-playing CB thing to get the attack to work properly. Now that we concede easy goals because of it, you come crawling back u cheap sack of shit (its sunny reference, not to be a dik)