What is the reasoning behind choosing an “inbox-organized” approach instead of an “inbox zero” strategy in building Shortwave?

I think in many ways, we do view your email inbox as a to-do list. In most email clients, you don't really get the tools to manage it like that. You end up with a wall of chronologically sorted threads, and each one is its own independent unit. This essentially means you have a laundry list of work to get through. It doesn't give you any power to treat this like a to-do list that you don't want to bring to zero right now. 

We want to focus on inbox-organized so you essentially know that if anything is new, you need to act on. Otherwise, you want to have a list of work that’s prioritized the way you want it prioritized, but it doesn't necessarily mean that it’s all done right now. Very few people are ever going to get through the whole list. Especially if you're a person at a business where you have a long list of stuff you want to build, you're not going to get through all of your to-dos on any given day. So we’ve built features which support not getting through everything.

An example here is being able to drag and drop in the Shortwave inbox and change things from the chronological sort and make it so you can sort in any order you want—being able to drag one thread on top of another one and create custom bundles, where you can name it and write out the task that you want that’s related to these two threads, instead of having them at different parts of your inbox.