I consistently hear people on YouTube complain that the subscribe button doesn’t do anything for viewers, now that channel notifications are controlled by the bell. But it does do something: it puts the videos from that channel in your subscription feed, which is readily accessible on all versions of YouTube. So why do people act like it doesn’t exist? I think it’s super convenient, especially if you’re subscribed to a ton of channels and don’t want your notifications feed flooded with new videos.
I both use subscriptions and watch what the algo shows me. According to a lot of big YouTubers I watch, their viewership mostly comes from people who find them organically and only a smaller amount of their views come from subscribers but sponsors like to see high subscriber counts as well as high view counts.