> just want to point out that maintaining a knife is a whole hobby that requires a time investment of learning the skill and storage of additional tools and materials.

Properly maintaining a knife does. Most people don't need to properly maintain a knife. You can do it good enough with a honing steel and some crappy automatic sharpener.

I enjoy cooking good food for my family and myself, but cooking is not a hobby of mine. So if my knife can slice a tomato without crushing it, then that's good enough for me. I don't need to shave a tomato so thin that the slice is transparent.

Does the crappy automatic sharpener work? Well the knife cuts better after I use it, so yes, it does.

Yes as I mentioned I use often-recommended knives (victorinox, shun) and have them occasionally sharpened professionally and at least in my case the ultrasonic knife appears to solve some very real problems that knife maintenance cannot.