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.
Bitcoin no be altcoin make u sabi that one.
Make i also correct the OP say, USDT self no be altcoin in terms of utility, but na stablecoin.
The way altcoin be now, aside from the popular ones wey dey now, most new ones just dey turn out to be shitcoins wey no carry value and very risky to begin put our money inside, me sef no go want refer any naija person to invest for there if e no be Bitcoin.