Probably since before it was called "agile". In the 1990s I worked with an amazing group of people who taught me unit testing and practiced CI before they were called that. When the XP book came out, a group of us at another company began practicing those ideas.
I'm a speaker, trainer, coach, and author. I spend most of my time training and caching high-performance agile teams in industry. I created and teach the course Agile Software Development at Harvard University. I've played all kinds of roles: director/manager of tech teams, PO, SM, architect, code writer, tester.
It looks like my living room https://kasperowski.com/the-best-of-the-best-family-size-team-in-a-family-size-space/
Post-its, Sharpies, and walls
Yes! Communication bandwidth is so much higher when you're face-to-face with each other. Something like 80% of our communication is nonverbal: facial expression, body language, and more. The first value of Agile is about individuals and interactions. If you want great interaction, optimize for it.
The team knows more than me. Trust them. Facilitate their awesomeness, and let them do the rest.
The post-Agile world is about positivity, psychological safety, and team emotional intelligence. These are the underpinnings of Agile, and they're coming to the surface. Without them, it doesn't matter how much of the Agile sauce you sprinkle on a team. In the future, we'll be focusing on these things explicitly, and teams will become awesome faster.
I love helping people unlock their amazingness.
The most important book of our time is Software for Your Head by Jim and Michele McCarthy. It's the guide to high quality interactions between team members. Teams that practice the behaviors they document are the best teams in the world.
I'm a big fan of Michael Sahota--his work on leadership is important, another step in the future of Agile. I've also learned a lot of important ideas and practices from Woody Zuill, Lewellyn Falco, and Tim Ottinger.