Everyone thinks that their intro is awesome and makes their channel look more pro. They think it adds something to their channel. I fell into this trap at the start too. I, along with everyone else who thought that, was wrong.
YouTube is not a TV station and there are different expectations and viewing behaviours. You have precious few seconds to hook a user, so why waste those with flashy graphics at the start?.You need to immediately hook the user. Give them a reason not to move on. Have you ever watched the typical user use YouTube? It's brutal - just "next, next, next" until they find something that captures their attention. You must capture their attention. An intro does not do that. It adds no value. It can serve only as a negative. It's an opportunity for something shinier to catch their eye and then bam - you've lost that viewer. My own stats showed retention loss at exactly the point that the intro kicked in.
If you want subscribers, you need to hook people by getting them stuck in a cycle of your videos before they decide "hey, this channel is pretty enjoyable and consistent, I think I'll subscribe." That's how most subscriptions happen. Even if someone makes it past one of your intros, do you think they're still going to be super impressed with the same intro for the 5th time in 15 minutes? They won't be.
What you can do, is hook the user and then have the intro. Even then, keep it to 3 seconds or less - seriously. But even then, think carefully about what it actually adds to the viewer experience. It might well be worthwhile from a branding perspective, but it might not.