The good news about testing for poor connectivity and average user devices is that it can be emulated. The Chrome, Edge, and FireFox developer tools all include some capacity to simulate slower connections and even lower powered devices.
Chrome has the best developed conditional testing tools. In the Developer Tools, you need to toggle the device toolbar. The keyboard shortcut is Ctrl + Shift + M and the button is located in the top left corner. It looks like a phone overlaying a tablet:
This changes the browser tab to render the page in a frame. The frame simulates the viewport of a target device. ...
