BEING RESPONSIBLE IMPOSES RESPONSIBILITY:

The Delta variant spreads far more rapidly than "classic Covid."  So a given "small effect" of a mask is more important.  It used to be that a mask (sometimes) stopped the spread to one person, who in turn might spread to 1.3 others.  Now, if your mask stops the spread to that person, it might be stopping the subsequent spread to seven other people (we don't know the exact number, but yes I have heard "seven" bandied around as a possibility).

To be clear, in this scenario masks are still less effective than before in preventing Covid spread.  But the rate of return on wearing a mask, relative to no mask, can be higher.  It is simply that the whole curve has shifted downward in a disadvantageous way.

Under some plausible numbers the protective potency of wearing a mask might be about five times higher (seven divided by recent non-Delta R, or something like that).  Unless masks are five times (or more) less effective in stopping spread, masking could become more important rather than less important.

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