Mollygo
If you usually make soup by your preferred pan and blender/slow cooker/ pressure cooker, and you’re happy with that, then a soup maker is unlikely to appeal.
If you don’t usually make soup or you want to make soup in a one operation/no need to watch the pan/or wash multiple utensils method, then a soup maker will be a good idea. It’s not too expensive so even if you only use it for a year you have had your moneys worth.
I'd bet that is why soup makers exist. Some people fancy them.
Some people are in the kitchen, perhaps readying the next meal, washing up from the last meal - they use that time to make soup. They likely don't mind washing a pot and spoon.
I make soup 3-5 times a week - with recipes. I chop my herbs and veg, I measure carefully. I'm not fast. I'm content with methodical.
I usually don't make smooth soup, except tomato from my frozen summer harvest. I saute the onions and garlic, roast off the measured peeled tomatoes (I freeze them peeled), add herbs, boil, puree in blender. Wash out the pot and blender jar. Done. Perhaps a soup maker could be easier, but I don't see how.