MacOS Big Sur cannot use wifi adapter device
Some types of kernel extensions – including USB Networking – are deprecated in macOS 11.
These kernel extensions have to be rewritten by the vendor using DriverKit to be compatible with Big Sur. See https://developer.apple.com/support/kernel-extensions (USB networking).
While macOS 11 is in development, you can enable the loading of deprecated KEXTs by disabling SIP. See https://developer.apple.com/documentation/macos-release-notes/macos-big-sur-11-beta-release-notes (Deprecations).