Argument as a pointer to a true concept

In quite a few places you claim that if there is a serious debate going on about any issue (for example, moral questions), this is evidence that the basis of things is an objective and real concept that has existed for years.
On the one hand, I tend to be convinced by this argument, however, it has happened more than once that very serious debates have taken place about nonsense and nonsense, which calls into question the validity of the type of argument I presented above.
I would love to hear how you see the argument in question (perhaps it could be said that this is only a supporting argument and not a decisive argument)