Men and women just recently have been paid the same for their matches in tournaments. This has led to men including Andy Murray to suggest women play the same length of match as the men if they are getting paid equally.
As far as strength and endurance are concerned, I believe it is pretty relative. Women compete in strength and endurance competitions just like men. The overall time, weight, scores, etc. may be lower for women, but it is relative. Women would wear down in long, tough matches just as men do.
By the way, Martina Navratilova thinks that men should play 3 instead of 5. Women's tennis has more rallies and longer points. Men's tennis has more aces and shorter rallies due to greater power in each shot. If women had five sets, their matches would tend to be longer than men's matches.
