It is, when our team was full of great players it played great with Allegri in his first season. Then we had Dybala and prime Pogba and Marchisio, it was fantastic football too. The it declined, to match the decline of our midfield. It's normal.
The only reservation with Allegri for me in terms of playing "great football" is the transfer market. The coach should be supported, we made this mistake with Sarri and Pirlo. The question is to what degree.
In the end Allegri is the one who chose Van Bommel over Pirlo at Milan, and Khedira over Marchisio at Juve. His choices in squad building are the only suspect part of getting and backing Allegri 100%.