Well, you did try and close a door to a possibility. And you tried to frame that as being “scientific”. Yet, you cannot prove it.

Science never has final say on what’s impossible. Until (if ever) we have a grand unified theory that perfectly coheres all we find and ever find, you cannot claim to know of an impossibility.

For example, an easy proof you’re wrong would be simulation theories. In that case, the Big Bang is just a sub-simulation inside a bigger universe. Can you prove we aren’t in a simulation? If not, then you cannot make any claim about how it’s not scientific to talk about before the Big Bang. We just don’t know, so taking the positive is an error.