It's not at all difficult if you have gained the basic survival skill of cooking. I mean, take a couple egg yolks in a double boiler, add the juice of a lemon, whisk until it's thick then add butter. 10 minutes and you can use a bowl over the pot of boiling water you're poaching your eggs in if you don't have a double boiler for your camp stove in the wilderness.
But that's still more of a hassle than putting the carton of that yellow plastic liquid in the microwave for a minute and a half. People will prefer their slops and the farmer brings it right to you; what could possibly be a better life?
I short-circuited my microwave accidentally two years ago (don't power it up and then drop screwdrivers) and that was the best thing to happen to my meals.
And that's ten minutes every time someone orders a dish with hollandaise because it really breaks when reheating as well. Given how much cost of labor is a factor it's easy to see why hardly any restaurant will serve real hollandaise. Perfect Baumol cost disease example. Maybe something like a Thermomix could solve the economic problem of hollandaise.