Why not just use Bitcoin?

I don't know what experience you have with using fiat or other currencies other than Bitcoin. For me, they have not been good experiences. I don't know how much your fiat currency has devalued? The one they give me has devalued to the point that the average salary of workers here is only enough to buy 30 chicken eggs and 1 kg of sugar. Those with minimum wage can't buy more than 15 eggs.

I only see the other cryptocurrencies chasing Bitcoin from afar, so I don't know what the advantage is of having something other than Bitcoin.

BTCLNAT

Imyourfed

AskSN

If we already have Bitcoin, why do we need anything else?

I wouldn't encourage anyone to use anything other than bitcoin, but the lightning network is a work in progress and using/building on it requires a lower time preference than most people, even bitcoiners that know better, are capable of.