I think the biggest problem for teams is his transfer value. Paris Saint-Germain is demanding a very high fee for a player with one year left on his contract. The team is unwilling to pay that amount. Otherwise, every team would want Donnarumma. He's a goalkeeper with the potential to even play for Real Madrid. In fact, if Barcelona were to sign him, they wouldn't have a goalkeeper problem for a long time. He's a goalkeeper you could put on any team and play. The only problem is the price they're asking for him.
The asking price is indeed quite high. But I think Premier League clubs will be able to afford him. Currently, Manchester United and Manchester City seem interested in signing Gianluigi Donnarumma. However, I'm not sure about the time remaining in the transfer window, which closes on September 1st. There's only one week left, so any team hoping to complete a transfer this season must act quickly before the window closes.
However, Gianluigi Donnarumma himself seems quite interested in a move to Manchester City. Talks between the player and Manchester City have apparently already taken place, and everything is going smoothly. We also know that Manchester City could lose their goalkeeper, Ederson. Therefore, signing Gianluigi Donnarumma would eliminate Manchester City's goalkeeping concerns.