Using USB device on MacBook Air 2020 w/Thunderbolt

Use the USB-C to USB Adapter (USB-C and TB have the same physical plug, but TB can carry more data). There are many 3rd party versions, as well.

Yes, it sure can be annoying ...

A "brand new MacBook" is designed keeping not only the latest technology available in mind, but also where tomorrow's technology is heading, and so it is usually not encumbered with ports, and connectivities that are perhaps going to be replaced in the (near) future. Hence, USB-C

But how to address users of older/erstwhile technologies like the USB, for eg. which is fitted on printers, TVs, hard drives from yesterday. Hence the adapter: USB-C to USB

Of course, the middle path, you could say would be to include both ... but then tomorrow you'd have features on your Mac that are just adding to the clutter when it could be "simple and so Zen!" Hence, the dilemma ... you already know Apple's inclination! :)

You will have to use an adapter: USB-C to USB. See this: USB-C to USB Adapter - Apple

and for some other USB-C accessories: https://www.apple.com/search/usb-c?src=alp