Ordinarily I would agree with you - shop somewhere else. Unfortunately, in the Pittsburgh region, Giant Eagle has a near monopoly. There aren’t a whole lot of alternatives.
I happen to like Giant Eagle (4 within a 10 mile radius) the best because of their curbside pickup service which allows you the opportunity to totally avoid jerks of this nature.
Shop ‘n Save, Wal-Mart, Aldi’s. However, I believe all those stores also require masks.
We were in West Virginia last weekend, where Wal-Mart’s policy was, “Masks recommended” (but not required).
That's the South Hills.
I guess it depends on where in "da burgh" you are.
I live in Washington Co. an hour south Walmart, plus 2 smaller markets are the only option 12 miles in any direction.
No masks required, though.