We definitely need him. But not only him, we need a lot in the midfield. Matic fell over a cliff really and Herrera is out, Mata is good but not a powerhouse week in and week out, and forcing Pogba to stay isn't gonna solve our problem it's just a bandage that will peel off in the middle of the season and the wound will be bigger and much worse. We've been here before.
I would suggest offering Pogba to Real Madrid in a swap deal with Casemiro plus 60 or 70 millions. Get Bruno for that 60 millions and sign Rabiot on free (as he's a free agent). Pogba's wages can be split between Rabiot who is asking for 190k/w and Bruno 100k/w. Casemiro is currently on 90k/w so we can offer to double his wages without breaking the bank. 3 players who will transform our midfield and make it far better than the shambolic state it has right now, and we won't be spending much. Good football deal and also good for our pocket, to free the cash for other demanding positions.