Yep, I agree with @Nikhil Sharma, unless they have changed things recently, the QR code on the back, is only used when activating the SIM card in their app which they use to register/activate the new connection or sim change etc.
In case of Airtel you can activate eSim completely online without visiting the store which is something I really liked. For Jio have to visit the store.
I have a question, what happens if you accidentally delete the esim profile or you lose the phone? Or if you want to switch the esim to another phone?
Airtel says "The QR code is unique and is applicable for just one time use on one device only. ... Customer should not select "Delete" option from the eSIM settings as this will permanently delete the eSIM profile"
So it seems like both Jio and Airtel requires you to visit a physical store to transfer an esim to another device. So if you're abroad and your phone dies, you'll be stranded. A physical sim is the best option there.