Chemical reactivity isn't the only thing at play here, in fact I'd say it's more burying the lead (kekek) than addressing the issue at hand. Sure glass isn't the most inert material, but another piece of the puzzle that is often neglected is mechanical abrasion. Once that surface has been compromised, the microplastics come right out.

Glass has the benefit of very high chemical inertness while also being extremely resistant to mechanical abrasion. Some types of glass are clearly not good enough (eg most 'crystal'/lead glasses), but borosilicate and fused silica are certainly well proven materials.

Another process that is relevant, leaching, while considered a 'chemical process' does not actually involve any kind of 'reactivity'. It's governed by solubility and statistical mechanics.