Are plastic-free or glass kettles actually better?

Reviewers in r/PlasticFreeLiving and r/tea favor stainless or glass interiors to avoid any plastic taste, and verified-purchase reviewers repeatedly confirm Cosori's stainless and borosilicate-glass models keep plastic away from the water. Glass shows scale buildup more visibly but is easy to monitor; stainless hides marks but isn't see-through.