Actually rain doesn't affect Jio AirFiber's performance, imho. My parents' phones and TV (for OTT benefits) are connected to that WiFi.
The only issue with them is. it has to be restarted once - every two days, without fail. Since I am in TN, where power goes off for 5 mins, minimum twice a day, all I need to do was "Just NOT connect the modem / router to UPS connection" and everything is set. BSNL FTTH and Airtel Fiber are connected to UPS.
Problem arose during election days (March, April, May), when TNEB gave uninterrupted power supply and it was a pain to remember to switch off and on the JioAirFiber setup once every 2 days. But from June onwards, power cut is back to normal and zero issues in AirFiber now.
AirFiber is Good as a backup connection, during cable cuts of your primary Fiber connection and can never replace fiber. Another use case is if you are in remote place, where there is no fiber providers (incl Local ISPs), AirFiber is your only choice, till any fiber reaches your place.
There is a great chance that, Jio AirFiber performance may improve after July 03 tariff hike.