No expert, but a "traditionally" constructed roof needs some type of
support in the form of a beam or Load-bearing wall in the house.

Support for a roof built with engineered trusses comes from the "sides"
of the house, and is distributed that way, so you wouldn't need a
"load-bearing wall" in the house.

A caution, I am not much of a carpenter or builder. Just repeating what
my contractor told me when he build an addition to my house that
included engineered trusses.