Madonna doesn't do the same dance move for hours she is always styled for the shoot, totally different to what Britney is doing
Madonna has had a huge amount of cosmetic and surgical intervention. Her business, certainly, but one could argue that it's less mentally healthly than how Britney Spears is living. She also posts a lot of far, far more provocative imagery such as crotch shots, exposed breasts etc, again her lookout but it makes a nonsense of tutting at Britney Spears' behavour at more than twenty years younger.
She's also nothing like Nikki Grahame from Big Brother - yes she's a bit childlike but she's a healthly weight, in fact she looks overall physically very healthly to me which would indicate good self-care.