Transaction logic is better although more of a pain. When sending Grin you know it was received. When sending other cryptos, it could be just a random address. Sadly this style of transaction may never be widely adopted. Just needs some make-up and widespread compatibility. We also need real-life use!! Think one of the opensource or rebel communities. Jailbreaking, Rooting, etc. 
-Macker
Great idea, maybe it could be incentivized by some sort of android grin mining app that is also a node and a wallet?
Edit: Whoaaa considering 1 and 2, phones could include asics + grin could be run, mined, and stored all on a smartphone…Users could earn on their phone by exchanging battery power for grin. It’s like portably running proof of work on battery power, and the light weightiness + privacy are the added incentives. Plus the logo is so great.
Grin is “doomed” to succeed because there are still so many people who invest in anonymity and will soon turn to privacy coins in general. I recently read about the pressures of cryptocurrency exchanges companies from governments. Very high taxation but also pressures to provide user data (what happens does not contradict the reason for the existence of cryptocurrencies??). Ιt is the end of an entire era as we knew it.
Grin is easy to use, fast and anonymous.
Maybe creating a platform for anonymous exchanges between cryptocurrencies by promoting Grin will help even more in the future 
I come up with an idea