Eh? Firstly there are plenty of “natural” or organic epoxies that can decompose.
Secondly that’s not the point.
Glass is a very energy consuming process, it’s heavy and a PITA to transport and it’s also a very good heat conductor which means for insulation you need to use multiple glass sheets with an air barrier.
This material is lighter, it’s a way to sequester carbon, it seems to be less energy intensive both to produce and transport and provides better insulation from the get go.
If this can be developed as a drop in replacement for window glass alone it can likely save a lot of energy both in the manufacturing and then in the heating of homes.
Even if it’s not biodegradable not everything needs to be, most glass isn’t recycled either, and it’s not like glass recycling is a particularly cheap process.
The glass from your glass recycling bin is usually just crushed and added as a filler to other materials not melted to make new glass.