Phones are the way to go.
ESP32 is cool but still out of reach for those regions, whereas androids you kick any stone and find two of them underneath.
It would indeed be interesting to see them all mining XMR.
Discussion
That why I love monero. Every device can be a miner, and everyone can pool mine and earn some xmr. Coming from South Africa, there's a lot of smartphones and people looking for ways to make money
Yes, monero in my opinion is the only cryptocurrency worthy of that name.
The rest are just casino coins, not really made for the people on the streets.