Pele is famous because…

He played beautiful football and is considered the best player Brazil ever had.
He not only played well, but was decisive.
He was considered by many the best player of the 20th century, or even the best athlete in all sports for the century (L’Equipe, COI, Reuters).
If you ask any football player that saw him playing who was the best, Pelé will be most commom answer by large.
He excelled in all football moves: dribbling, passes, headshot, etc…
He scored 1282 goals, 0.94 per game. In 1961 he achieved 1.63 goals per game.
He was a key player in at least two world Cups (1958, with 17 years), and 1970, while he is the unique player that won 3 World Cups (including 62).
He was a key player in one of the best teams in world football ever (Santos of his time), two times world champion
Pelé appearance in the world scenery, in the 1958 World Cup, at age 17, was decisive for the Brazilian victory. Therefore, he was a myth in early age.

If you want, imagine that a player that can even be considered better than Messi had won 3 World Cups and you would understand the dimension of Pele for football.