Because a lot of people who follow the sport have convinced themselves that "major trophies" are all of equal importance. The reality is that there are 3 major trophies for English clubs to win and they are the League Title, the CL (European Cup) and the FA Cup. And clearly the FA Cup is not comparable to a title.
The word success is used to have clubs like Tottenham seem more important than what theyve actually been in their history. Technically are more successful if all honours were equal but quite clearly they're not.
Villa are the closest to us for important honours with their 7 titles and European Cup. Followed by Chelsea.
Our past success is becoming less relevant as the years go by though. A shame that the club has gone through this spell. Even a League Cup would do as we arent winning a top trophy any time soon, if ever again.