Quite a nice cautionary regarding data truncation. I've seen enough data loss due to the data items being placed in unfavourable environments, even when such an issue may not be immediately obvious. Ultimately, it usually happens to all of us at least once, though that doesn't mean we shouldn't avoid it at all costs. Worst case scenario, hope it wasn't the only copy of the data.

Interesting high level look at consistency, concurrency and availability models. Quite a decent explanation of the same, useful as a "cheat sheet", so to say, when studying such things. After all, the map at the top, once the concepts are understood, should be enough to act as a guide in analyzing a system of your own, be it a student, such as myself, or someone who needs a quick refresher.

I don't see anything wrong with the majority of asynchornous communication methods. Mind you, I'm a fan of slack and a lot of people aren't. The issue though, I think, and the reason why slack is so widely used despite the fact that most users tend not to like it is because of the UI. It's friendly and easy, for surface level tasks, and that's far more important to people than the fact that it's synchronous (based off of my own experience, can't cite any stats so I'm not making a claim here). Email could very well work for this, and several apps have tried to "IM-ify" email, but none have really caught on. It's a UI and UX issue fundamentally, not a capability issue, once again according to my experience.

I presume that energy density also has a lot to do with it, as others have said. Other ways that we've tried, including hydrogen cars, just don't offer the same amount of energy density. Real volume constraints are also becoming an issue as we need more and more energy for devices. That coupled with improvements in safety and cost makes it worth it.