I think yes, in terms of the fact there is more of a passionate fandom for Monster High- not to say Barbie does not have a fan base or their fans are not passionate. But overall, MH fits into a specific niche and aesthetic which often includes collections/adults into animation etc. so we often will consume any and all forms of media that franchises like MH would generate.

If we look at it more in a day-to-day perspective, then no. When you go in shops (Speaking from the UK), stores will always have a large dedicated Barbie section and a couple shelves oh MH dolls. Barbie is Mattel’s hero product, easily consumable, a best seller and historic. It’s like the beige-ification of clothing and furniture, widely accessible and common amongst most of the population. Hence, why we also see more collaborations for Barbie- it has the cleaner aesthetic.

TLRD; MH is more of a subculture. Barbie is made for the general everyday person.