Alan Katsura, Moderator, CA Diablo Valley Chapter
I'm just a volunteer moderator for this group. I do not know the history of the decision on using Groups.io. I do know the person who was probably associated with setting this up is very capable.
I'm not familiar with Google Groups so I cannot go through the advantages and disadvantages of each platform. If you are considering Google Groups because you have a G Suite for Nonprofits (formerly Google for Nonprofits) it might be nice to have as much as possible in one place for your chapter. A glance at Google Groups leads me to believe Groups.io has more features but you may not need them.
Hashtags, chat, polling, photos directory, files, databases, and Wiki are features I did not see in Google Groups. The calendar is no longer included with the free Groups.io plan. It is grandfathered into our plan. The HLAALeaders group uses the calendar feature to create a national calendar for chapter meetings.
Moderator HLAA Tech Group