A bic pen isn't a bad pen, it is stunningly successful type of pen.
There are meaningful differences between how it feels to write with a fountain pen or other type of nice pen vs a bic but there is no reason you might not just prefer how a bic writes.
I like the relaxed, but controlled feeling of a fountain pen. Writing with bic like pens my whole life I got into the habit of gripping the pen hard and pressing down hard and it made me hate writing.
There are meaningful differences between how it feels to write with a fountain pen or other type of nice pen vs a bic but there is no reason you might not just prefer how a bic writes.
I like the relaxed, but controlled feeling of a fountain pen. Writing with bic like pens my whole life I got into the habit of gripping the pen hard and pressing down hard and it made me hate writing.