And yet, somehow it was the standard method of operation for more than half a century before plastic bowls became widely available.

I feel bad for those poor 1940's housewives, all hunched over and disfigured from dragging 200 tons of Corningware to the church potluck supper.

Unfortunately, borosilicate glassware is more difficult to find, so even if I would like to use it exclusively, besides some borosilicate items like teapots, double-wall glasses for hot or cold drinks, glass vessels with glass lids for microwave cooking, I still use other heavier items made of tempered glass, e.g. bowls, other sizes of vessels for microwave cooking and rectangular vessels with glass lids for storing food in the refrigerator.

You are right that I normally do not carry food away from home in tempered glass vessels and this is the only purpose for which I use polypropylene boxes, but when I have a borosilicate vessel of suitable size I do not hesitate to use it. Even if it is not so light as PP, the weight is manageable.