Sure, but those bicycles don’t cost 100 bucks they probably cost 5000+. The last bicycle I bought was $7000 and that was midmarket (my recreational cyclist standards).
However some of what they are spending money on would make those bikes in Rwanda much better. Better/more comfortable seats can greatly ease the toll on your body. Disk brakes would stop the load much better and so make them safer. A couple gears would be nice (assuming it doesn't compromise drive train strength too much). Modern cargo bikes likely have a better cargo position as well.
Living minimally is a skill that society has essentially turned into a negative trait. Our planet can only support so much, and individual humans are very selfish. There are 8 Billion now.
Is it desirable? Not necessarily. The goal is to be more efficient with water sourcing, distribution, and usage so people have more water to use, not less.