No, Szczesny is better.
He and Buffon were the best GKs in the league last season. Szcz was the best shot-stopper, and Gigi the best overall. Donnarumma is the same as last season currently, didn't make any quantum leaps in a short period of time.
Besides, we can't even afford Gigio's salary. PSG threw 12 or 14m at him in summer.
It was a brilliant, smart move. He's good, well-acclimatized in the league and is also spending a year with us. There'll be no van der Sar like scenario.
Not all of our keepers will be a Zoff or a Buffon. Sometimes, it'll be a Tacconi.
Sign Meret or another young GK with potential. Let them develop. Meanwhile, Szczesny will remain a good, safe pair of hands.