Postpaid is always better. For one, you get detailed billing. If your ISP also provides landline phone along with internet, it is very useful.
Airtel Vfiber bill is detailed - gives date wise calls made, std, isd,, data used in a month, etc.... You can plan better with this kind of set up.
Jio billing is is not user friendly, maybe that is how it is designed. You recharge, and all they give you is a copy of invoice. To get to additional information, you have to keep digging in my account section, to display other details.... This is a pain for the elderly and for folks with limited internet skills.
A company would usually take a deposit for postpaid services, since there is some credit involved.. What Jio is doing is taking a deposit for prepaid services. It is akin to budget airlines (giving very limited services) charging full service charges like full service airlines.....
For example, look at how you log into your Jio account on the web. You give your registered number, receive otp, enter that otp to log in.
Why do you have to do this every time you log in? A simple login username and password would have sufficed. What does Jio have to gain by sending an otp sms every time you want to log in?