She was better at every aspect of acting and completely blew Sridevi out of the water when it came to dancing, a huge part of being a Bollywood actress.
Madhuri has an ATBB HAHK where she was the hero of the film and blockbusters like Beta, Raja and Saajan where she completely overshadowed the heroes and carried the films on her shoulders. While Sridevi has a few of her own such as Chandni and Chaalbaaz.they are nowhere close to Madhuri's body of work.
Sridevi, while very popular came nowhere close to peak Madhuri assisted by her blockbuster numbers from "ek do teen" to "dhak dhak" to "choli ke peeche". Madhuri was the highest paid star in the early 90's, she got paid more than the heroes of those time.
She's easily the biggest female bollywood star of all time.
57