Some gadgets are worth it, some are complete garbage. You can normally tell one from the other by questions like "is this thing easy to clean?", "will I use it much?", "would a chef use it?". If the answer is no then it's probably junk that will live in the cupboard forever.
"Would a chef use it?" is the acid test. If the answer is "no", then find out what a chef does as a workaround and do that. Instead of buying an electric garlic chopper, learn how to chop garlic with a knife.
The piece indicates that she does actively use them. He just wants more counter space. Basically the issue here is a shortage of cabinets and/or shelving, imo.
I suppose also then the question "do I have space for it?". I have a bread maker and the thing is enormous but then I make GF bread with it so it's a justifiable thing to own but I couldn't say the same for an ice cream maker for example.