I've spent some time reading the docs and still don't understand what Dapr is. Is it something like jBoss Fuse but for cloud era?

Of course, I'm not entitled to good documentation for open source project, I realise it. But let me just share my personal preferences.

When I encounter new library/framework/service I want to know 2 things:

1. What problem(s) does it intend to solve?

2. What are the closest alternatives and how this thing compares to those alternatives?

In most docs I encounter it's either hard or impossible to find this information.

Dapr's solving distributed systems development at scale. Basically as you grow your team from a handful of people to many separate teams all working on different products, the technical architecture also evolves from monolith to SOA and then microservices. It's the natural logical evolution of anything at scale. Dapr is attempting to provide the primitives you'd need to build any sort of software at scale. Usually this buckets into; authentication/authorization, configuration, data storage, pubsub messaging and a handful of other things.

Full disclosure: I'm the author of Micro (https://github.com/micro/micro) which bakes in the same primitives but also focuses solely on development in the Go language.