1. Nigeria has 30 MILLION people that use it. Most of the usage is for cross-border transactions. 2. transaction rate limitations only apply to the settlement layer. retail does not need to use it, only very large transactions that need high settlement guarantees.
Lightning network has essentially unlimited tps, currently has close to 1 million (!!) live nodes, and even sub-penny transactions are perfectly viable because fees are even tinier or can be even nil.
Live LN stats: https://1ml.com/
If you truly do care about lives of 4 billion people on the planet, you should at least internalize these basic facts, as you are simply repeating misinformation: tps are low, no traction. it is simply not true.