For starters, maybe existing Game Jam mechanism can be used. Organize a Jam with the purpose of not to develop a new game quickly, but to show-case existing well-developed games. Maybe require participants to add a presentation or extended devlog, explaining the specific unique aspects of their game they want to highlight and discuss. In the 'scoring' part, encourage participants to leave in-depth and detailed reviews of each other games, hopefully starting some high-level discussion. While not a true conference, this seems to be a comparatively easy first step.
Viewing post in A GDC but for Indies? Minus the Screaming.
Would be easy, but does not encourage discussion.
There needs to be a go-between other than to work tirelessly on a title to speak beyond things left 'in-depth' for scoring as it then just feels like someone's school assignment. There needs to be more communication; I guess is what I'm getting at. Setting up such a thing as an event, I get; but it's all a bit one-sided.
It is not entirely true.
Usually there is open space for folks to interact with the speaker; usually to clarify or get some idea about what's going on. This is also true for any conference or con outside of this scope, Anime Conventions typically have this type of dynamic between professional/speaker and the audience whether it's asking questions trying to find love at said con or the specific's about asking the bare bone basics on how to setup an object using the abstract constructor's of a class for a newly created engine someone is presenting from the ground up.
Even then, there's been a bit of a rise in new engine's; mostly because the monoculture of talent coming out of college are either use to using Unreal, Unity or Godot for their project's, not many of them or rather, non of them to an extent, have taken the time to understand the geometry and how to manipulate certain aspects of a mesh or model to both promote and show they understand animating a model beyond just rigging it to a skeleton frame and applying movement... But that's a different topic for something else.
There is typically a good guarantee there is a response from the audience than to have someone come onto the podium to speak, no matter the subject or the issue.