I've noticed that many small YouTubers, (and some larger), love to use incredibly long droning intros.
There is absolutely no need for this. Considering it just takes a second to read your username, and see your logo if you have one, it is quite possible to shorten an intro to 5 seconds. Or less. But my word, I've seen intros up to half a minute on this forum. I think the most common length I've seen however, is 15 seconds.
Let's say a YouTuber was doing a gaming commentary series, with each video being around 10 minutes long. You have a 15 second intro, and 8 videos already up.
I've spent 2 minutes total watching the same annoying intro, when I want to be watching the actual gameplay commentary.
I understand if a YouTuber uses an intro for branding, but you may still shorten it, and still have it look fancy.
If the YouTuber is using the long intro so the viewer remembers who they're watching- well, they can read your username under the video, and if they want to subscribe, they will, and don't need to be told.
I personally do not use intros.
In my gaming commentaries, I say "Hello, it's Obscur" anyway. So an intro would just be telling them that twice.
In my skits, its not important who I am, so I don't introduce my channel. When they finish watching the content, they'll comment, like, and subscribe if they enjoyed it.
I do use an outro as of late. The viewer has already seen the content they came for, and if they haven't checked for my username yet, now they know.