What is the difference between raw.hbs handlerbar files and only .hbs handlerbar files?

That observer is not ideal as we are trying to get away from them as we continue to upgrade Ember. I think a better way is to create a helper and put your JS in there. Here is an example
https://github.com/discourse/discourse-category-experts/blob/main/assets/javascripts/discourse/connectors/topic-list-after-title/category-experts-indicator.hbr