In my opinion, the hasty jump from bitcoin to VBcoin and others essentially bypassed the built-out of layers on the top of bitcoin.
Nobody ever expected bitcoin to do everything, but if financial rails were built on bitcoin first, it would have been much more "organic", imho.
Currently, "crypto" (apart from btc) is a disorganized mess with, unfortunately, lately developing criminality, like recent 'sniping', etc.

So, my position is that s-tcoin took something from btc, and gave almost nothing...for now.
Yeah, as an exception, perhaps they increased the velocity of money because people were constantly moving between s-tcoins and btc and then stables, as was rightfully noted, but i am not sure how important it was as far as the market size is concerned.