Is an EV with 80% battery still usable? I ask because phones with 80% batteries are practically e-waste, or urgently needing a replacement. It's not a fair comparison but that degraded battery in a phone is a problem, because the phone still requires a certain amount of power that the battery now struggles to provide and overheats, in many cases, causing secondary damage to other components (like the display).
Phone batteries have relatively little margin. If it lasts barely a full day at full capacity, going down to 80% means you can no longer reliably say "I'll charge it overnight".
A car battery that lasted 300km new but now only 200km is still entirely adequate for a commuter with a 25km typical commute, and occasional 75km days out.
