I don’t have a soda stream, but I do have a carbonation cap for my 1/8 barrel homebrew kegs, and have used it to make “Italian soda” (carbonated water to which you add flavor syrup/puree in the glass).
Basically the same thing, just a lot bigger. I can’t fathom a reason to not want to use it if you like sparkling drinks, it’s a lot cheaper than buying soda water or whatever. Especially if you aren’t buying single use co2 charges and throwing them away after. I guess that would be my only real concern, personally. I hate those things. Such a small capacity makes them very wasteful, even if they technically/eventually get reused.
You can get a used ball lock/corny keg, a carbonation cap, a co2 cylinder, and a pressure regulator, and make it 5 gallons at a time if you want. No support for Israel involved :)
Bit pricy, the whole setup you need will probably run about $100-200 depending where you get it, but you can put damn near any liquid in it and make it carbonated if you want. Wine, juice, water, sugar water, flavored sugar water, milk if you feel bold (tho at that point just make kefir, that’s nice and bubbly), beer, liquor probably…
Actually I just looked at the price of a soda stream and this isn’t that pricy by comparison… so there’s that.