The difference between “how” and “why” doesn’t seem very meaningful to me. For example- why does water boil? It boils because molecules gain enough energy through heat to transition states.
In that same sense, OP’s question
why there is something instead of nothing.?
There’s a non zero chance that we eventually understand the mechanisms behind the big bang and can explain how nothing turned into something. Therefore we will be able to explain the why, no?
But is that not the same way with “how”?
How do objects fall to the ground? → the Earth exerts a gravitational force on them
How does Earth exert a gravitational force? → All objects with mass create a gravitational field that attracts other masses
How do objects create a gravitation field? → Mass warps spacetime and this curvature directs objects to follow paths towards the source of the mass
and so on, etc