If we're looking for a proper comparison and barometer, let's take Wolves last season.
They were in a good position like us, only it was less of a surprise for them. Molineux was a fortress. It was very loud, the best I've witnessed since being back in this division. There's no reason we shouldn't be buzzing like they were. We've also had a longer absence from the PL.
Our Kop is shitter than theirs but that alone doesn't account for the difference. Our support now should be very similar to what theirs was.