And this is a thing since forever. Big4 are a thing for obvious reasons. This doesn't mean "nugu" groups are untalented, this just shows how a big company is a great deal in the beginning of the career and that's it. I don't know why this is still a surprising fact in kpop..
Obviously big4 aren't the only ones with talented idols, great music, etc, but they are the ones that can provide a big help and this help includes (not always) a good result since debut so yes.
Just saying. I don't want fights, but just saying.