It's all about the influence they had on a whole culture. Young people were enthused, many instruments were picked up, haircuts styled, girls wet themselves etc....
I enjoy their music but wouldn't place them in my Top 100 bands. Imho, George Harrison wrote their best stuff, followed by McCartney (who actually wrote alone a lot of the tracks credited to him and Lennon). The Get Back series on the tellybox recently was an eye opener in that regard..... Lennon had his moments but, due to his 'charisma', is held in undue reverence. YMMV etc.....