OF COS HE IS.
Even his peers are full of respect for him. If you consider steve vai, satch, andy timmons as great, they cite jeff beck as their influence. He has a reputation of "the guitarists' guitarist". Try to find someone who can use the whammy like him. Although vai and co. has surely surpassed him in terms of technicalities, vai once said if he can have 1 guitar lesson from any player, it will be jeff beck. take a pic. If anyone says jeff beck sucks it means he is saying he's better than vai and co. Plus, beck isn't restricted by any genre. There was a time when beck and hendrix were competing "who did what first", including using feedbacks and things like that. Plus, his style and feel is very hard to be copied.
To me he is the best player who can get the most out of the least notes played.