They definitely are not all made equally. Many slings are pretty poor, even from well known brands, as they don’t all promote healthy hips. Whichever sling you use must support your baby from knee to knee, rather than have them dangling from the crotch (I’ll add some pictures). It’s also really important that the sling you use supports the baby’s back and neck, without allowing their chin to fall on to their chest as this can constrict breathing.
You should check out if you have a local sling library as they will have lots of great choices to explore and knowledgable people to explain how each sling is used. Different slings suit different people, so it is a really personal choice as to which one you go for. Try to avoid buying off Amazonor eBay as loads of fakes on there, which are not well made.
My personal preferences for slings are a stretchy for when they are little (Moby, Boba, Joy and Joe all do these) and a Tula for bigger kids.
View attachment 454557View attachment 454558View attachment 454559