Armorstands are the only entity that have an hardcoded invulnerability with the Invisible NBT tag and cannot be broken, even in creative, despite similar entities not behaving the same with the Invisible NBT tag, like item frames, who can be broken, even in creative.

How to reproduce:

1. Summon an invisible armorstand using

   /summon armor_stand ~ ~ ~ {Invisible:1b}

1. Try to break it in survival or creative

Expected behavior:

The Invisible armorstand should still be able to be broken in survival and creative unless it had the Invulnerable NBT tag too, in which case it should be able to be broken only in creative