1. Cost of maintaining a phone- purchase one, keep it updated, get it repaired when it breaks, charge it, etc. You also have to purchase a new one whenever technology moves ahead and yours becomes incompatible. They are probably doing it purposely (planned obsolescence)? I see people buying new phones almost every 5 years (average price of Rs 11,263 or $ 159). No, you can’t buy burn phones. They don’t have smart features.
2. Cost of internet. Whatever monthly payments you make to your masters you can invest in a mutual fund. When I was in the US, I noticed that my peers were paying $30+/month for phone service. They thought they didn’t have money to invest. The worst part is they rarely ever called anyone. They were paying that much only to text. Texting is free. Just what are you doing?
3. Dependency on internet. If you don’t have connection at the time of payment, you need cash. You can never go off the grid. And we already know what internet is doing to people. It has turned them into cyborgs, like lab-monkeys scrolling down a screen to get orange juice. Furthermore, smartphones have created an avenue for personalized propaganda. Now, people can be brainwashed individually and privately. People no longer know what kind of sick propagandas their parents, children, siblings, and friends are watching. An image of a single mind controlling everyone by pampering their ego comes to mind.
4. Security threats from online thugs and primarily from governments. The biggest threat is governments, as we all know. They can take your money and defend themselves with man-made laws.
5. A dystopian future in which a centralized entity knows about every transaction you make. The moment you upload your information, it can pretty much never be destroyed. You never know how many copies of your data exist and who all have it. You can only hope that your bank or your UPI keeps it to themselves, but there are powers above them who can bait/lure/force them to release your information. We are not talking about dumb things you upload on Facebook but of important information like your address, phone number, email, and bank and credit card details.
Update on Nov 10, 2020 -
Repair cost only increases with time. Devices get old. Spare parts become hard to find. When you do find them, they cost more. If you can't find them, you must discard your old device entirely.