Again, don't mistake the ability to access a shared inventory to mean a chunk is loaded. That data is stored elsewhere.
Yes, stuff like Ender Chests is amazing and pushes the envelope, but people are clearly still expecting that it does more than it actually does.
I don't think you get it that some people don't need machines on both sides to be running constantly, I'm perfectly happy to go to the nether build a base that pumps lava, nether wart, and blaze rods into ender chests while I'm building, hunting, and or exploring and then when i return to the overworld my Generator tanks become filled to the brim, My brewery stand begins production of the many potions i might have use of along with any number of other thing all without me ever having to worry about having to stop, empty out my inventory, and fill it up with whatever nether goods where produced.
In short, It doesn't matter that they don't work it the same time, it would be nice if they did, but they don't and that doesn't negate the usefulness of the ender chest