I guess they have the same problem that Superfest glass from the GDR had, the glasses just don't break often enough.

Indeed.

I use only borosilicate glass vessels for cooking, for storing food, for eating and for drinking (some from France, some from Czechia).

I have replaced some of them in order to have more optimized sizes and shapes for the ways I use them (even if the replaced vessels were still perfectly good), and I have some extra vessels kept in reserve for the very unlikely case when I will break a vessel (which has not happened yet).

I do not expect that I would need to buy any more such vessels during my lifetime, unless I will become bored of those that I have and I would want a change.

So making money from selling high-quality glassware that can last forever is much more difficult than getting free money from a software subscription.

Exactly. All my glassware are Duralex including coffe cups, and I haven't broken a single glass in 25+ years. Yet, they regularly fall on the ceramic kitchen floor from a hip level.