WiFi-less AirPrint-capable Printer connected to router USB

Don’t blame Apple... as AirPrint is not designed to work over wired USB connections.

AirPrint is a network protocol (or more accurately, AirPrint uses a number of network protocols); it’s not designed to work with a USB printer - which is exactly what you have as soon as you rely upon the printer’s USB connection.

If you connect your USB printer to a AirPrint server (such as a Lantronix xPrintServer) or a PC/Mac that is emulating an AirPrint server, you’ll be able to print.

This might provide a useful primer to the AirPrint technology.

https://en.wikipedia.org/wiki/AirPrint

Check the App Store to see if there is an App from the printer company that can be used on the iPad for printing since the printer is not connected to wi-fi.

We are just uses like you, not Apple, so it isn't necessary to get hostile with your responses. The fact is that AirPrint is how the iOS devices work, and if your device is not connected via wi-fi to the network, then it won't work. If you wish to take out your frustrations about AirPrint, then you need to do that with Apple, and their feedback page is located here, Feedback - iPad - Apple Don't shoot the messenger here.

You’re missing the point.

If connecting via a USB connection, you are not connecting to the printer over a network interface - over which the AirPrint protocol “talks” to the printer.