Ask HN: How can we tackle feature fragmentation?

I've been thinking about what I like to call feature fragmentation: frequently I love specific features from different applications or services. I might hate the performance of a particular email client, but like the UI; I might love the workflow of an issue tracker, but miss integrations with other systems.

Can we think of a new software development and distribution model that can allow users to mix and match various features from different vendors (sort of like Feature-as-a-Service)? I have several ideas of how this might be realized.

This model might be most useful in markets with a large number of competitors, e.g., email clients, project management, issue tracking, todo lists, photo management.

For consumers, the benefits are obvious and many. I suspect this model will face resistance from established vendors, but for smaller and newer entrants, I argue that this approach might help them to sell to customers to might otherwise not use their software because of deal-breakers (e.g., a missing feature they can't live without). It also helps them to focus on their core value proposition. Even for established players, it is not at all clear that this is a worse business model for them; might require some business numbers crunching.