“What is this? It’s under the kitchen cabinet of the new home.”

And that is basically it!
Once it loosens, you simply twist the rest off by hand. And that’s it! No gadgets on the counter, no fuss, no cursing at a jar of pickles like it personally wronged you.
So, yeah, the lady who wrote about it somewhat inadvertently reminded a lot of people these can openers existed. Now a lot of people will be digging around their cupboards to see if they have inherited one as well. It’s like retro kitchen tech. No flashiness, no intelligence, no Wi-Fi or connectivity. It still does precisely what it is supposed to do. If I am being honest about it? That’s a little scarce these days.
Anyway, if you are lucky enough to find one of these in your new home, don’t rip it out. Just give it a clean, maybe tighten the screws, and leave it there. It may very well save you next time you wheel out the jar of pasta sauce that has a lid on it sealed tighter than a bank vault.