What popular or emerging web applications are built with the Elixir language and Phoenix framework?

Travel Agency Tribes - mostly runs on Elixir now. Was previously 100% Ruby on Rails. We support thousands of travel agencies in North America and generate thousands and thousands of leads for them every week with the online marketing we do for them.

The entire Analytics pipeline was rebuild with Elixir/Phoenix and Citus (Postgresql).

Most of our offline jobs now run with Elixir.

80% of our travel supplier data API consumption happens with Elixir jobs.

1. Is it possible to build an eCommerce website with Elixir and the Phoenix framework?
2. Is Elixir + Phoenix worth learning when you have to create very quickly web backends that scale to millions of users?
3. Conditionally render templates in Phoenix - Elixir
4. How much of the "Programming Elixir" book must I go through before I can start learning Phoenix?
5. Is Elixir (programming language) dying?
6. How do I learn Phoenix (Elixir) in a pleasant way?
7. What are some types of computer applications that will never be doable as web-based apps?
8. Which programming languages do you think will be worth learning in 2021?