Unable to install Event Platform Event Details due to unmet dependencies

I also tried the ddev composer require 'drupal/event_platform:^2.0.x-dev' but ran into the same issue.

It seems like this issue happens because we are missing a requirement on the core
layout_builder module. Which is not installed by default.

However, installing that fixes that issue, but brings another one.

Configuration objects (user.role.authenticated) provided by event_platform_sessions already exist in the active configuration

That issue is solved by moving the user.role.authenticated from event_platform_sessions from the install folder to the optional folder inside config.

I believe the issues you encountered should now be fixed on the dev branch. Please test it again.

I believe this should be resolved now, so marking this as outdated. Feel free to reopen if additional work is needed.