No it isn't. You could just as well compare how their teams do in Europe, watch games from both leagues or look how shitty the lesser teams are. For example in Serie A you have Parma and Crotone that have only won ≈20 points each this season. So are Parma and Crotone shittier than Eibar and Valladolid or are Inter, Atalanta and Milan stronger than Atletico, Real and Barca for example? I personally think it's more likely to be the former. I certainly don't think Inter, Atalanta and Milan as a group are stronger than Atletico, Real and Barca. Also looking at how Italian teams did in Europe again this season doesn't really help Serie A's case here.