Haiku does support WLAN adapters (even USB ones), through the support isn't as extensive as Linux or the BSDs. You might want to use the current nightly builds instead of the latest beta version, though, which was released in December 2022.
https://hardware.besly.de/index.php?hardware=Wireless_Networ... https://discuss.haiku-os.org/t/support-for-realtek-usb-wifi-...
Good example, the interface is incredibly snappy but no Wifi. I love the vision of BeOS but it probably would have been the death of Apple if they had gone with it.