> If it were a subsidy then Wendy’s would be closed during downtimes.
Which is what happens, many restaurants now close earlier, open later, close during the afternoon, or otherwise reduce hours.
> In general, prices are always about demand, not cost.
Prices are the intersection of supply and demand, with a lower limit being the cost of goods sold.
> Acting like the opposite is untenable is ridiculous, it’s the way the whole world works and has worked forever, except for one industry that gets away with everybody hating them because people have no alternative.
This is not true, spot pricing exists in many, many businesses. Obviously, the volatility of price changes is usually eaten by merchants at the retail stage in many businesses, but there is no need for it to always be the case. Many restaurants have "lunch menus" for this very reason. Even in theme parks, they effectively engage in a hybrid of spot prices by allowing people to pay extra to cut in line.
> It’s solely about increasing profits at the expense of customers, let’s not pretend anything else.
Yes, that is called business. No one accepts $20 per hour if they think they can get $30 per hour.
Supply and demand curves are constantly in flux, regardless of how often Wendy’s changes the prices on its menu. The only question is how much utility the merchant thinks they will get from eating the cost of the volatility versus letting customers be exposed to it.
A kitchen surely has a fixed limit to how much food it can serve up, so the supply has a cap, which a higher price can be obtained, which means the merchant can better compete with other businesses along other lines, such as investing in the facility, paying employees more, building more restaurants, etc.
And obviously, the barrier to entry in the food business is extremely low, and the prices people are willing to pay are relatively low, so even if Wendy’s managed to extract a few extra percentage points of profit margin from more accurate pricing, it is not going to turn into a trillion dollar business.