Requiring a wipe is by design. If an attacker steals your phone, whats to prevent them from flashing a new system partition that lets them read off all the exi

Requiring a wipe is by design. If an attacker steals your phone, whats to prevent them from flashing a new system partition that lets them read off all the existing data? You can backup most (all?) of your data manually, then unlock and restore the data. Otherwise unlocking would be essentially the easiest attack vector to owning a device without the user knowing.