I agree with most of what you're saying, but here in Canada, chicken breast is so not cheap.
If I have spare time on a weekend it can be picked up far cheaper in bulk from a food services supply store. 2 weeks ago when I last walked through the cooler section it was sitting at $1.29/lb in 40lb cases. Costs maybe 10 cents per food saver vacuum bag or so to freeze them in packs of 2-4 each.
A lot of folks are price takers and have forgotten how to comparison shop or buy on sale and stock up. These were skills lost over the past few generations - likely since stores thought they were competing on price far more than they actually are. Covid taught them the average consumer simply isn’t as price sensitive as the business classes teach you, and have engaged in aggressive price segmentation.
I don’t bother buying most shelf stable or freezable products these days unless it’s on a very large sale - which I’ve found tends to happen roughly quarterly for most things. Beef is the current exception, but we buy a half cow from a local farm and eat off that for a year or more.
If I have spare time on a weekend it can be picked up far cheaper in bulk
from a food services supply store.
I just checked around and for boneless, skinless chicken breasts:
Sprouts $7/lb.
Safeway $7/lb (more if you don't want the chlorine treated stuff).
Trader Joe's $7.50/lb (but they've gained a reputation for nasty, woody chicken).
Whole Foods out of stock.
Lucky's $8.50/lb.
Mollie Stone's $8.89/lb.
Berkeley Bowl $9.59/lb.
US Foods Chef Store $3.75/lb for *twelve pounds*.
I swear my growing boys have hollow legs. How do you eat more than I do?
Chicken well raised and fed, is usually good starting at around 30-40 EUR / kg. I supermarkets selling 1kg of chicken for 4-5 EUR / kg - I would not touch this.
Animals held and then sold for 4-5 EUR per kg is pure shit. Period. I would rather eat groceries instead.
Most people have no idea what high quality meet is because they buy their stuff always at large chains - remember: None of the sustainability-interested local farms sells to any of those supermarkt chains. You have to GO there to get your stuff.
Such animals you can also eat without having remorse.
There is the thermodynamics of calories in and out. Then there are micro nutrients.
Everything beyond that is bullshit marketed to suckers.
Also, depending on how the animals are fed, you have different substances in the final product, like Antibiotics.
So feel free to optimize only for the "thermodynamic calorie perspective" ;-)