People staying in metropolitan cities like Delhi, Mumbai, Kolkata, etc. have been enjoying stable internet all along. So, it's easy for them to judge Jio when it comes to 'quality' and 'morality' stuff. Ask that to people from villages and even small towns.
When I used to go to my grandparents' village, I could hardly use 2G internet on Vodafone and Airtel. To place a call, I had to go out to the terrace. Even that was patchy. At my town, every network was usable more or less (except BSNL 3G of course) but cost a bomb. We had no internet except for the trash BSNL
ADSL. Fast forward to August 2016, when my Mom bought a LYF phone. A free to use jio sim card came with it. Mind you, Jio wasn't launched yet and they were providing unlimited data to one and all. It was the first time in my life that I saw the Ookla Speedtest meter climb to 60 Mbps!!! Now, when I went to my grandparents' place, I could use Jio 4G, sitting inside my room. Even a 5 Mbps connection felt like a godsend for me.
While I do recognise the fact that mobile operators need to raise money for network upgradation and maybe Airtel took the correct step in being the bellwether of all telcos, where was Airtel all these year???? They were minting money till late 2016 and the ARPU was ~200 (more than that when adjusted for inflation) or somewhat satisfactory according to their terms, I suppose. Were they keen on upgrading their networks? NO. They continued to mint money from all and invested for network upgradation only in big cities. Airtel launched 4G in Kolkata in 2012. When did they launch 3G (read 2G) at my grandpa's place? In 2017-18. When did Jio launch? 2016 September. When did they launch 4G? Before Semptember 2016. So, yes. People stuck to Jio.
In fact, Airtel 3G wasn't fast enough before 2016. The average speed was ~2-3 Mbps even when congestion was low and they were charging a bomb. And yes, this was in Kolkata, where they were apparently minting great money. It took Jio's aggressive expansion for Airtel to expand their network footprint to villages.