DSA has the advantage of being all the same profile, there are not sculpted with different row shapes so it's much easier to move the keys around for the desired layout which is what seems to make it popular with users of non standard boards and layouts.
That really isn't possible with sculpted legend keys unless you don't care at all about having random row profile keys scattered all about. Now, GMK does have a uniform profile short spherical key similar to DSA... but the key sizes are extremely limited and don't cover all the sizes needed for standard boards so probably a non starter for anything else besides things like EDox, JD40, etc.