I'd say it is technically impossible to describe Existence Erasure in the scale of Attack Potency even with the use of Environmental Destruction as it is used for the attacks that cause the amount of damage dealt at a wide area. For example, a city-sized. However, the amount of environmental destruction's damage correlates with the given tier's description if we use the environment similar to our real life's one unless we are using exotic attacks, like, I don't know, maybe a gas that breaks the matter to subatomic particles via sheer energy?
The tier is very useful for describing Existence Erasure's (EE's) area of effect, but I think that EE and energy are different concepts. I mean, we could possibly describe EE as the work if it means removing energy (in a matter's form) from the universe's state (With a strong violation of the law of conservation of energy as the energy doesn't go anywhere), like how a hot soup loses its energy in a refrigerator (Bad comparison, but whatever...). But that means nothing in the practice.
If I remember well, the verses usually consider EE as the erasure of the embodiment, a certain being, something like that, relying on the amount of space, not the amount of matter, I guess.
Sorry of the amount of water I poured there, but no, resisting Existence Erasure doesn't scale to the durability.