Bitcoin can be mentioned not because it is low in transaction fee more than most altcoins but it is because is very high in profit as assets, investment and secured.

If I have to add altcoin that is still very important to Nigerian crypto space and transaction, I will say BNB because it has large platform and supports crypto trading, transfer, conversion etc and it has very low fee with coins on it Blockchain. The BNB Smart Chain is quite important in transaction and conversion.