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.
There was a period of time a few years ago (around whenever the bell was implemented, or perhaps caused the bell to be implemented) in which the subscription feed would often just not a show a video, or maybe it wouldn’t show up until hours or even days later. I suspect for some people that made them suspicious of the subscription feed and more reliant on push notifications.