I guess you haven't used when Airtel was upgrading network between 2016-2019. It was only when 2020 March, Airtel stabilised in Mumbai circle. Its not optimized as well. Unless and until you don't lock the bands you will have battery drain on Airtel network. Since Vi is integrated(January to March 2021), people have moved to Vi and hence load on Airtel network reduced and hence battery drain is reduced. Similar kind of issue it was there in 2016 when only band 3 was there and band 1 was utilized was 3G. There used to be continuous switch between 3G and 4G and hence it resulted into battery drain. Similar things will happen on Jio as well. 10Mhz on each 600Mhz/700Mhz plus 100Mhz in n78 is what Jio will take and if I know Indian smartphones very well(even for that matter Samsung), then Jio network will keep switching between n78/ 4G on band 40 and 4G on band 5 which will result into battery drain. Those who want to peacefully enjoy the Jio network can lock the band 3/n28/n71. But for sure battery drain will be there. Even though we can lock the mode to 5G but it will get by default to 4G for voice calls. VoNR isn't ready for many phones as well Jio VoNR is not as good as it seems to be. Have tried and tested it in Kamla Mills, so can confidently say that.
Also, people have recharged yearly in November. I doubt anybody will be in mood to switch to Jio 5G. Its just hype as it was in 2016, it has lowered down. Those who want quality network data speeds, prefer Airtel and Vi in city limits. Yes, Jio VoLTE and Jio 4G coverage is impeccable but even today after six years and rigorous planning of so many years, payment on UPI on Jio network fails at peak times in metro areas.