Useless "Fallback to default locale" checkbox

[ivankyrpa]

Hey all,

I've noticed the issues with "Fallback to default locale" checkboxes for non-default locale Array/Blocks fields while ago and would like to figure out the purpose of this feature. The problem is well-described here: #5155. It also relates to the latest versions of Payload CMS.

Questions:

1. Why is the checkbox unset when fallback feature is on?
2. Why is a user allowed to change checkbox value when it does nothing?

Maybe it makes sense to show the actual fallback state for the field and disable the checkbox if it doesn't change anything?

Thanks in advance!