You can now delete a field from a collection, click the vertical ellipsis in the header for the field and select Move to Trash.
Except the field is not really deleted, which can create issues down the line. Let’s say that you create a field called “Clock Name” which will then have a Field Key of “clockName”. Due to requirements, you change the field name to “Atomic Clock Name”, but the Field Key cannot be changed, and remains “clockName”. In order to change the Field Key, you have to delete the field, and create a new one. Except… if you try to create a field called “Atomic Clock Name” so you can get the new Field Key of “atomicClockName”, you can’t because the field “Atomic Clock Name” was not really deleted, just hidden. Wix allows you to restore the original field, but that does not give the answer you need. So… it would seem that either we should be able to change the Field Key (just like for fields on a page) or Wix should really delete a field from a collection when it says delete.
I agree, it might not seem like a big problem because there is always a workaround, but it would save a lot of time.
I don’t understand why WIX does not allow to permanently delete a field. That does not make sense at all. I hope they add this feature soon.