What if gold armor was made better than iron, but would get worse the lower the durability is?
If we bumped all the stats of the armors down like you are suggesting, how would you put bedrock armor in? As long as we nerf current armor, I wouldn't mind having something similar to bedrock armor. Just with the changes I specified in my other comment on this thread.
You clearly put a lot of thought and effort into this suggestion, for which I applaud you.
I do agree that the armor system is bland and needs updating. I think we should try making other kinds of armor more useful since they aren't used very much. However, I don't think a solution to the armor system is to add something that blocks this much damage. The thing is, a full set of Protection IV diamond armor already makes the game feel too easy (even when on hard difficulty) and thus creates boredom. I also feel like people would get bored trying to find this new armor since there isn't that much of interest in the end.
I cannot stress enough how rare Bedrock Armor would be. The average post-Ender Dragon Minecraft player may never find Bedrock Armor.
This is what I am referring to. People would either 1. Try to get it from a few end bunkers and then give up or 2. Get lucky and find it with in the first few bunkers. This is why I don't think making something rare is a valid way of balancing a powerful item. This type of balancing works with wither skeleton skulls because it is a rare drop from a common mob, and they are used to spawn something that is dangerous to everybody, including the player who spawns it.
Something that I definitely think you should tweak in your post is the fall damage protection. I think that is pretty crazy, and it would just seem weird to see a player drop down from an 80 block tower and not take any fall damage.
Overall, I like that you put a lot of thought into this, and I enjoyed reading it. I also really (and I mean really) appreciate that you used correct grammar and are understandable in your explanations. However, I can't say I support this.