As far as registrations and voter role purging goes, I don't see why we can't sync voter registrations with drivers license or other ID expiration dates. Many states look at whether or not a registered voter cast a ballot in the last 2 general elections and automatically purge them from the roles. Could have moved, died, been incarcerated, or simply opted out of voting.
I think there should be an ID requirement, and the ID expiration should be linked to registration expiration. If you renew your state ID or license, your voter registration will also be renewed.
It's simple to send out renewal notices for expiring registrations, which would catch anyone who's not renewing their ID (forgot, etc).
These are just examples of how simple a solution could be. Unfortunately, the states are not applying resources to find solutions. The purges, therefore, have experienced errors by purging valid citizens' records.
So, the question isn't whether or not the roles need to be maintained by purging records for those no longer able to vote legally in the state, but rather the state's are not coming up with proper processes to do a role purge while creating a fall-back for anyone who is at risk of being incorrectly removed.
Find better solutions instead of screaming about the half-ass solutions. Doing nothing makes elections very susceptible to fraud.