It does! (less water, so less hydrolysis) "name brand" syrup however isn't particularly economical at retail however[1]. Not too surprisingly there has been a rash of restaurant bankruptcies during the pandemic and so buying "used" soda fountain gear is actually pretty easy (at least in the western US) these days. I actually have an Elkay "water machine" which does carbonation (as well as chilled and not chilled still water) although its carbonation chamber is too small to give a good fizz like the commercial units do. (more Perrier like, less fountain soda like). That said there are also relatively few powder mixes that take into account carbonated water. There was an AWESOME Grape Crush one (that was sugar free) but since it tasted poorly when mixed with still water it was discontinued (having a soda water tap is not the normal situation).
One of the more interesting ideas (and also impractical) are the "mini-syrups" that are used in the multi-beverage dispensers with the touch screen at places like Movie Theaters. Good luck getting hold of those. I briefly had a line on getting them from a local AMC because I knew the manager who wasn't averse to re-selling them to me at cost but she changed jobs when the pandemic made theaters non-viable. The existing Coke branded dispensers are so loaded up with various DRM/telemetry that even if you can get one at auction (which you normally can't since they are leased, not sold) it would be quite the reverse engineering process to get it to work "disconnected" from the Coke network.
[1] Funny story about how I spent four months trying to buy Diet Dr. Pepper syrup at the "restaurant" rate (which was about 1/4th the "retail" rate) elided.