When I got a playstation 2, my stepfather was amazed it had a blue led. They were crazy expensive just a few years earlier and this console just used one for no real reason other than it looked good.
At least in the US I'd say it's because the government pumps billions and billions in subsidies to the different farm sectors (70+ billion a year for beef alone). The products you mentioned don't get that funding and don't sell the volume either.
I'll bet dimes to dollars that it's not that hard to turn grass into labmeat-consumable nutrients. Cows use bacteria to digest grass, anyway, and enzymes are usually pretty easy to make in a lab, too.
IMO the biggest customers for this once it reaches parity with real meat for cost and quality will be companies like McDonalds, Sysco and other companies that manufacture foods in biblical quantities. Once they can save money by doing it, they absolutely will and once they start putting their level of investment into the tech, it will advance very rapidly.
Its possible they will open with that, "cruelty free cultured beef" or some buzz term that sounds better than lab grown. But beyond that think about it on a McDonalds level industrial scale. If they can make each pattie for just 1c less than real beef and they make 2.36 Billion burgers a year...
With real beef they are still at the mercy of weather, diseases running through herds, they have to move the stock, slaughter it, process the carcasses then process the meat. Shouldering the costs and losses the whole way in their margins.
If they can get it to work at sufficient scale McDonalds can build a "lab" with a pattie factory attatched, hell if they can they will grow it pattie shaped. They know "lab grown" isnt a selling point yet, they wont shout it from the rooftops.
Milk comes in contaminated and you have to kill the existing bugs.
With this process, it starts out by killing off everything on the equipment with heat treatment, you then grow your sterile "meat" in a sterile environment.