USB On-The-Go was proven right to be used in different models of tablets and smartphones but not all. With this feature the device could be connected to pendrives, external peripherals like mouse or keyboard, or special devices like thermal cameras, sound modules, mixers and other gear.
It's really not nice how the industry keeps the OTG models away of the most affordable hardware and doesn't implement it in platforms where it would be easy, keeping multiple users away of this functionality. Also observable how memory like 32 or 16GB is a factor to sell more expensive units, when the memory at this level now is really cheap and there are 512GB SD cards in the manufacturing line. With OTG anyone may connect a pendrive to have more memory, or even a hard drive.
Internet by means of wireless is not mandatory if you connect a modem, avoiding Wi-Fi radiation if possible when you are in places with ready cables, by far more stable and with more speed and security.
The good news is how models like the Samsung S3 or others now have a 30 or 20% their initial price and that allows to have a unit with OTG for a reasonable price considering how the market goes dropping it month after month.