agree totally with you, Allegri is nerfing our ability with his 3-5-2 obsession, I always thought of the guy as a lover of attacking football but seems like since he came here he is so scared to lose/fail and is still under Conte's shadow to totally implement his own ideas in our play, you have certain people try so hard to see positives in the 3-5-2 that totally leaves our strikers completely isolated that the opponent usually always is pinning us back in our own half and that's even mid-table and small clubs, these same people that defend the formation strongly know in their hearts it won't get us anywhere in Europe, its a shame how they defend it everyday in and out, even our best European days have always been whilst deploying a back 4, if we can't beat today's Serie A clubs with a back 4 then its a shame, we don't need 3 men defending all the time when we have some intelligent attackers who cannot express themselves to the best of their ability because a damn formation holds them back..
Well I think after all this time I've found out the term for the problem this club is having to extend the superiority in domestic competition to europe, it all boil down to this :
This club has a supranatural innate ability to chameleon it's play style to match whatever level of opponent it play against.
When we're facing bigger (not in relative to ours but in general) clubs we often can match them.
However very often the same thing happened when we're facing smaller clubs, it doesn't matter whether it's sevilla or benfica or hamburg or fulham or galatasaray or palermo or noejarsland whatever; very often this club no matter what squad it has, this club would simply somehow chameleon it's way to become the same level with those lesser clubs it play against and were having far too much problem on those matches that it should be on paper.
Look again at those smaller clubs I mentioned above where we were having troubles in the last a decade or so in europe.
How many times the likes of real barca bayern or even english sides + psg and others at those level were having such big troubles against those kind of clubs??? How many times did they play against those team and when they were at it, somehow they managed themselves to look like a midtable team in the process like we repeatedly done?
Seeing the pattern being repeated, you gotta ask what exactly is wrong?
IMO the problem came from the cultural and mentality of this club and calcio in general, the emphasis on defence, the neglecting of attacking flair and modern wing play, also the too much "self restrain" / respecting the opponent and such, the reactive approach to games instead of being pro active... I don't know about you but IMO those are at the counterpoints on how other big continental clubs are doing/behaving (of course with the exception of atletico)
Maybe some of those factors cannot really be proven, however there is some evidence for that, like the complete lack of quality italian attacking players atm, the lack of italian wingers (berardi insigne bernadeschi are only above mediocre, heck there even no good italian striker atm lol).
This is no longer a matter of personnel qualities, this is cultural / mindset / mental problems.