The problem with RoR is still a Basecamp Framework. Even though it is used by Github and Shopify. Things like ActionView-Component [1] couldn't be merged because it is not used in Basecamp, even though it is used in production at Github. Auth / Devise as mentioned is another one. Active Storage problem is another one, ( which leads to Paperclip stop being maintained )

[1] https://github.com/github/view_component