From 2007-2014, the default and only retention option for iPhone texts was "Forever." This changed with iOS 8, released September 2014.1 At that point the automatic cleanup options were functionally 30 days, 1 year, or 7 years.
Today, this option is 30 days, 1 year, or 18.5 years. Since 2014, photos have gotten a lot larger, as have videos. iMessage will perform some size mitigation depending on context2, however it doesn't touch standard HEIC/JPEG images.
The iPhone (2007, "2G") took photos between 400 and 800KB, and at launch didn't even support MMS.3 A modern standard iPhone photo is frequently in the 3-6MB range. Across that time, directly sharing pictures also moved from being the realm of email/flash drives/DVDs to the realm of texting and cloud sharing.
iMessage itself had only existed for 3 years in 2014, any messages before that were only "green bubble" SMS/MMS. This further reduced the capacity to send images and their maximum sizes upon delivery across the initial 7 years.
Messages in iCloud fixes this problem locally for iOS devices. However, any Mac with iCloud sync enabled will try to fill the drive with sometimes hundreds of gigabytes of messages + attachments. It will even regenerate the attachments folder entirely if you delete it. The messages are unsearchable if they aren't locally present, regardless of platform.
I think it might be time to at least consider 2, 3, and 5 year options. It might also be time to consider detaching "keep text only" from "keep attachments" in this selection, as well.
Footnotes
- How to Delete Your Message History Automatically (2014) ↩
- Videos will be compressed to a lower resolution depending on length/size. Sometimes videos get embarrassingly blurry as they approach 1 minute. ProRAW will send as a much smaller JPEG. ↩
- Multimedia Messaging Service added the ability to send photos, videos, and audio. This came in 2009, and photos were heavily compressed in comparison to what came later with iMessage. (Capped at 500KB or less typically.) ↩