The Big Bang theory says that time, space, and matter/energy all originate in the same singularity, not that they all originate in “nothing.”
And I’ve seen several philosopher make the case that such a singularity is ontologically equivalent to nothing. You are just question begging.
Because time and the material universe had the same origin, it can truthfully be said that the universe has no “beginning,” since there was never a time when it did not exist.
“Almost everyone now believes that the universe, and time itself, had a beginning at the Big Bang.” (Stephen Hawking and Roger Penrose, The Nature of Space and Time,)
I think I’ll go with what the expert physicists say.
I’ll go with what the expert physicists say too. The catch is that sometimes, when writing for a non-technical audience, you have to sacrifice strict technical accuracy in favor of readability. That’s why meteorologists, despite being heliocentrists, will say, “The sun will rise at 6:52 am” instead of saying “At 6:42 am the earth will have rotated to a position relative to the sun such that a line between the sun and the eye of an observer of average height will no longer intersect the body of the earth.” Though the latter version is more technically correct, it is so needlessly complex that it actually obscures the information we’re most interested in knowing.