15% of the world self-identifies as having a disability. The most common category of disability is mobility-related. E.g "going to the and entering the store" may not be as easy as it is for you, or even impossible. Even if you don't have a mobility problem and can do that just fine, for other people "ordering and dealing with complications" is a lot harder if you have trouble hearing, or have facial paralysis and can't speak, or even if you just don't speak the local language fluently. There are a million reasons that might make the simple task of getting food impossible for a person, and there's way more people out there who experience things like this than you might guess.
Maybe you simply never saw these people in person previously, because they weren't able to order from you at all. Maybe you just assumed your customers didn't have a disability because they didn't say so. You have no idea how many people ordering from you have disabilities. You can't know. Assume it's one out of every 4 people you meet if you live somewhere poorer, because that's realistic.
When mobile ordering went online, it meant that so many more people were able to choose what to eat, which meant more business for restaurants, which meant restaurants needed to staff their restaurant sufficiently, or upgrade tools. They don't just get to enjoy the extra profits for nothing.
And yet your frustration is directed at the people who are just trying to eat. I would like to offer you a reframing of this situation and suggest that your problem is not with customers at all.
Customers ordering shit we ran out of
People can't be expected to know a restaurant's stock inventory. The responsibility is on the business to communicate that to the customers. Some restaurant's make the cashiers say it in person to every single customer. Some restaurants erase them from displayed menus in the store. These days, restaurants can just tick the box "unavailable" in an app to let all future and present customers know immediately. It can even be scheduled, or automatically respond to events like "removing the last pack of an ingredient from the fridge". These options all exist already, your employers need to figure out how to use them properly, or the software they use needs to add these features, or they can just not accept online orders when the restaurant is too busy. Your beef is with management or the order service companies they use.
shit we no longer offer
Same deal, but an even worse look for your management for not ensuring they tell their delivery services that something is permanently gone. Your beef is with management or the services they use.
setting the pickup time 5 minutes after placing the order then getting mad when it’s not done on time.
Still a software and management problem. They need to be able to set minimum waiting times, and management needs to update them if they know the restaurant is too busy. Your beef is with management or the services they use.
All this while we can’t communicate with the customer at all until they arrive to find the order incomplete because we couldn’t contact them to figure out what they wanted to do.
I have ordered online and later received an automated notification when the restaurant has had to extend waiting times unexpectedly.
I have also ordered online and then had a restaurant send an automated notification that a specific item went out of stock after I ordered and asked me to choose an alternative item or just leave it off the order. It also automatically recalculated my payment when I decided to leave it off. No in-person interaction required.
These features all already exist. It's up to the managers of the restaurant to use them and to take the burden off the people they manage. It's up to the owner to only use companies which provide useful tools that don't harm their employees and customers. It's up to the software companies to put features in which don't harm customers and restaurants.
Your beef is with management or the services they use. You are misdirecting your frustration at the only people in the situation with the most reasonable time-sensitive important problem out of everyone involved. None of the problems you listed are the customer's fault, they have no idea how your workplace runs or what is normal for them.
Start a union instead of blaming people for ordering food and you might not have to experience years more of the same.