Greedy iOS Message Storage Results in iPhone Storage Full

I have a 64GB iPhone 12 XS with 1 TB of iCloud Storage. I have iCloud Messaging turned on, yet my message library is taking up 33% (20GB) of my iphone (and iPad's) storage. I even freed up a few gigs by removing unused apps and duplicate videos/photos that were in my message library. Ultimately, this actually made my Message library storage larger on device. I'm thinking cause there was more free space, so messages though it could keep even more assets on device. This was only a few days later, so not like I received 3GB of messages in those few days.

How do I keep my Messages library from being so greedy with my on device storage? I don't care how large it is in the cloud, but I don't need 20GB of message history on device. Not to mention, my iPhoto library is 131 GB in the Cloud but on device is only 5GB. My understanding is that iMessages in the iCloud is only supposed to keep messages on device if there is enough room, similar to Photos, but this clearly isn't working. I'm constantly butting up against this device storage limit because messages is just taking too much.

In the Messages Preference, I have Message History setting in Messages is set to "Forever". My understanding is that this setting is synced to all your devices and also affects your messages in the cloud. Changing it to 1 year would delete ALL MESSAGES over a year old from ALL DEVICES INCLUDING THE CLOUD. Since messages are not stored as part of the backup when iCloud messages is turned on, this would also mean that these messages would be unrecoverable. The ramifications of changing this across other devices and in iCoud is not clear and completely understated. If it in fact is a setting across devices perhaps it should be with the iCloud messages setting and they need more clear language.

Does anyone else have this problem and how do you keep imessage from eating all your on device storage.