The new WiFi installations do not run old protocols. Surely they may support the older versions, but by default the newer protocols are used. Compare that with IPv6 when after 20 years the protocol is still disabled by default on ISP provided routers in Europe.
Usually, devices have an "802.11n+" options nowadays, dropping support for 11b and 11g has some benefits. It's often enabled by default on new devices, especially since most 11b/11g devices don't support WPA2-PSK so couldn't connect anyway
Has WiFi been upgraded? I believe new devices still have support back to 802.11b.