Fun fact! While the Barrier does exist in the Legacy Console Editions of Minecraft, the barrier seen here is NOT "minecraft:barrier". The actual barrier texture directs to terrain.png. The barrier sprite here is actually a debug item called "minecraft:fourj_debug_item", and you can actually obtain this with inventory editing. Unfortunately, it seems that any functionality that it had was stripped from the retail updates, but it's still cool I guess. It also happens to share a numerical ID with Java Edition's "debug stick" (2255), credit to my buddy PhoenixARC for the ID coincidence discovery.

Edit: So I stand corrected! Shoutout to my buddy Pirlo for this. Turns out it apparently updates an entity's PersistenceRequired value to true when interacted with an entity, which stops an entity from despawning naturally