I feel like that was a cool and unique enough mark for original subreddit to give it a different vibe than most other communities with similar intent.
It also helps standardizing the titling format just enough to make it less confusing and clearer when reading them. Now that there is a brand new modding team I feel like this could be a good thing to add here
At first I thought that seemed unnecessary, but I subscribe to a lot of “question” communities, and knowing right from the start that I’m reading something from ELI5, would let me know the context of the question I’m reading.
Whether or not that’s worth forcing title formats, I can’t say for certain.