I agree with you that Georgia is a "GREAT" state and after living in over 15 states and 2 locations overseas, I would not live anywhere else!
As for your question, Bob is correct. The MLS service is the culprit. This is due to all of those in todays world that look for small miscues so that can file a lawsuit. But, if you or a buyer do want to know the square footage of a property, it can almost always be found on line at the County's Tax Accessor's web site. Some newer properties may not have the complete information, but the majority will of existing homes will. You can access the information using the address, owner's name, parcel number, etc. Another method would be to go to the county office and search the records there. The folks that work in these offices are always very helpful.
I would caution you that as a seller, I would not quote square footage to a buyer. Also, initial buying prices and motgage amounts are listed in tax records and providing this information to buyers may give them an advantage in the negotiation process. If a buyer wants "all" of the particulars, let them or their agent gather that. You should be concerned with staging, curb appeal, comparables and pricing, accurate property disclosures, etc.
Have a great "Georgia" day and if you need any additional information, let me know.