> Boom, you're practically guaranteed not to get it.

Not without eye protection you're not. You're also practically guaranteed to wear the respirator incorrectly. Wearing them correctly requires training, absence of facial hair and enduring a very significant degree of discomfort.

You're completely ignoring the part about not being indoors with others unless necessary. You're practically talking about dressing up in a biohazard bunny suit like you're going into a COVID ward, but that's just flat-out not necessary if you aren't remotely putting yourself into those kinds of hotspot situations to begin with. I assure you, someone taking these kinds of sanitizing precautions is already not putting themselves into close contact with other people, and is thus already getting most of the gains even being considering masks at all. Then add on wearing a good mask when necessary and you reach the 99+%.

I deliberately made no comment on the necessity of wearing the respirator in the first place - that's a separate question. I'm simply saying that if you're going to the trouble of actually wearing a respirator, do it properly.

As for the need for them - anything at or above the N95 respirator level (including eye protection) is only useful in environments with a high probability of contamination. That's mostly healthcare facilities with known C19 patients (particularly in proximity to aerosol-generating procedures), patient rooms, etc.

EDIT: I think I may have misunderstood the intent of your original post. You said "N99", so I assumed you were actually talking about respirators. If you just meant surgical masks, we're mostly in agreement.

> You'll get 99+% of the possible wins

Can you provide hard evidence for the 99% number? It agrees with my intuition, but I don't think we have a very complete view of the effectiveness of different measures, and in the absense of such evidence it seems strange to authoritative call someone else's measures "excessive".

To be clear, I don't think what the commenter is doing is very useful, but I can't prove it either.

You missed out handwashing, which is an important part of preventing the spread of infection.