the great mask debate

No one said these masks are the cure all to stop it.
They help control the aerosol spray produced by talking, sneezing, and coughing. It means if you wear one you have somewhat of a chance of not spreading or getting it then not wearing one.

As far as the curve goes. Yes it lengths the time period, it doesn't mean less people will get it. It means that it gives the medical facilities a better chance to to treat more people over that period and not put a strain on them. Which mean possibly more people would survive it.
If people would also understand that not going to crowded areas such as parties, bars,rallies, etc. would help too. Which is just plain common sense
which appears that a lot of people in this world don't use.