I’m sure it could be done. But can it be done at anything other than boutique scale and pricing? That I doubt. It’s like the old saw about most things, you can get stuff that’s high quality, you can get stuff quickly (or long lasting), and you can get stuff cheaply. Getting all three is a feat worthy of the gods!
I’ll use a concrete example. I have, on occasion, made duck confit at home. It was… pretty cheap, I bought two frozen ducklings from the Asian market, at around $2.99/lb (pre-COVID, I think it’s 3.99 or more a pound last I checked), made confit with the legs and most of the fat, and ate the rest in various dishes and made incredible stock from the carcass.
If I want it from Williams-Sonoma (not the most expensive, but not the least either), that’s $79.99 for 2 lbs. Sure, it has nothing in it, but duck leg, rendered duck fat, garlic, shallots, salt, sugar, spices.
It’s probably amazing. It’s also $40 per pound, and that’s for a version without canning or other longer term preservation.
Now sure, tomatoes, gravy, and the like tend to be made with much less expensive ingredients! But you also have to factor in the cost of creating all the equipment and personal to make it, to process it, to put it into shelf-stable storage, and ship it around the state / nation / world while making a small / medium / large profit.
And since a lot of those factors can’t be shorted, it’s almost always the ingredients that get the deep cuts early on.
I’ll give a better example. @Beckdawrek says they can make an amazing gravy. If you paid Beck, say $30 + shipping per quart jar, I’m sure she’d make some from scratch, home can it, pack it in dry ice and ship it to you. Probably a few times.
Or, I’d do the same with all the from scratch tomato sauce I made with my MIL’s tomatoes (bushels worth, while reduced quite a lot).
But if you needed enough to supply more than just yourself, we’d have to get help, equipment and all the other trappings to keep up with demand. And very quickly, the people who manage all of -that- start running the business, rather than the cooks and chefs that -may- have been involved in the beginning. And they care a whole lot less about anything than growing said business and improving the bottom line.
Dammit, we should go back to getting all our goods from monks working breweries and cheeseworks under a vow of poverty!