Is it really important to manage hair loss in the early stages?

I'm worried because it seems like I'm losing a lot of hair little by little lately.

People around me say that it is most effective to manage it early, but others say it is okay to wait and see a little longer, so I'm confused.

For those of you who have actually managed hair loss, when did you start? I am curious if starting treatment immediately upon even the slightest suspicion was helpful.