I see you've had a lot of comments disagreeing with your assertion that email is a bad way to have a discussion. I think I understand your point, and I too feel that my discussions are most effective in-person, followed by video chat, followed by phone, and finally in last place written simply due to the varying absence of body language and voice tone.

That said, I must disagree within the business context simply for the following reasons, all of which effect me daily in my career:

1. The Internet is global, the world is global, not everyone is a native English speaker and it is necessary to be very clear, and give sufficient time for understanding. Written communication facilitates this by being asynchronous and providing a pathway for transliteration. In my current role I interface with people across more than 60 countries to get large, complex, technology and engineering tasks completed. Email (and to a lesser degree Slack) is essential to this.

2. I work remotely, as do many of my peers, this makes a face to face conversation basically impossible. As a rule, an office culture of having face to face conversations as a preference subtlety devalues the contributions of remote workers and creates a separate political hierarchy within the organization based on higher rapport from face-to-face conversations and the availability of the "hallway track". By building a culture of written, asynchronous communication, we ensure that /all/ employees are on equal footing across the company both politically and materially.

3. My technical projects are of sufficiently high complexity and need a very high level of shared understanding, and that complexity is difficult to communicate with accuracy and precision in spoken word, as it often needs illustrative images accompanying an explanation. Rich text and images together are far more effective at communicating this complexity than speaking to someone. Better yet, is often a demo done via screen sharing or screen sharing for pair programming work.

4. Everyone is busy and has their own personal biases and priorities, as applied to the workplace. To ensure everyone is moving in generally the same direction and aligned to the company goals and team goals, it's important to have accountability. Providing information in a written form which is traceable (email) helps drive accountability and provides everybody involved a point of reference to help them stay on task.

5. An email inbox can act as a rough to-do list / priority queue, and face-to-face conversations act as interrupts on that queue. While you might be "more effective" at getting the things you care about done by talking to people face-to-face, you're doing so at the expense of other things they could be spending their time on which may be higher in the priority queue for the organization. What is most important to you personally within work context may not be the most important thing to the company. Forcing a face to face conversation is taking advantage of the rules of etiquette to manipulate the priority queue.

Just a few things to take into account. I think every work environment is different, and it is also easy for us to be biased into a belief that the most effective thing for ourselves is the most effective thing for the organization. This isn't necessarily the case. Often an organization gains net efficiency by using less efficient processes at an individual level which scale more effectively and have inherent checks and balances for accountability, and email is one such case. There is a reason why email is so prolific, basically irreplaceable, and hasn't really been dethroned since it become commonplace.