He looked very aged in the Venom movie and that may be the last we see of Stan Lee unless he already made his cameo in Avengers 4.
Stan Lee was an absolute innovator of comics and was the one who made comics big back before world war 2.
A pause from Stan Lee to share infobreak from antiquity:
Today is: 29th May (GMT), in history on the 29th of May, 1912 AD the following event happened:
15 young women fired by Curtis Publishing for dancing "Turkey Trot" during their lunch break