There's no doubt that YouTube is the most-watched platform for sharing videos, and while there are many things users enjoy about this platform, there are many things users don't enjoy, and one of those things is the constant suggestions of channels you probably have no desire to watch, especially if they don't really pertain to your interests. YouTube is finally letting you remove these channel suggestions so you can get on with watching things you actually like.
This is a change that YouTube will be rolling out in stages, as it'll be making its way to Android and iOS today and then in the future (presumably or perhaps hopefully in the near future) it will be rolling out to the web version of YouTube. The downside is if you use YouTube more on your laptop or desktop, you'll still have to deal with channel suggestions that you may not have any interest in, for now.
Getting rid of these channel suggestions will be a pretty simple task. When one of these suggestions pops up all you will have to do is tap the three dot button along the side of the panel the video is in and a new option will be sitting towards the top that says don't recommend channel. And that's all there is to it. From that point forward you won't receive suggestions for that channel.
With that said you may still get other suggestions about channels that you don't care for, so you may need to do this multiple times, but some of these suggestions you're seeing may be due to the fact that they are channels which have been liked by other users that have similar interests to you.
While you may still not want these kinds of suggestions and will still be able to remove them going forward, YouTube is going to tell you why these suggestions were made so you at least have an understanding of it. This is certainly not a bad thing. It will allow users to make a more informed decision about removing a channel suggestion, and who knows, after reading why the channel was suggested based on it being liked by a different viewer with similar interests you may want to continue letting those suggestions come through.
Essentially how it appears to break down is that if you watch a particular channel, YouTube will tell you that a channel was suggested because other users watch it and a similar channel that you're interested in. So if you watch a channel like Binging with Babish and get a suggestion for How To Drink, it's quite likely because other Binging with Babish viewers also watch How To Drink, and YouTube will inform you of this.
YouTube is making one other change along with the two above, which is that you'll be able to explore topics for channels from the main home screen of the app. These topics will be listed at the top of the page when you scroll up and can be for anything from baking to DIY, and selecting one of those topics will take you to a new page that will show you videos from channels that fit into that specific category.
Though the channel suggestion removal feature is showing up on mobile devices as of today, the rollouts for the other two are a little different. For instance, the explore feature that lets you view videos based on topics is hitting Android today but not iOS or web versions of YouTube. It'll be rolling out to those later on. The reason for why a channel was suggested to you is only available on iOS today and will be rolling out to Android devices and desktop later on.