I'm not annoyed by notifications in the slightest and they're incredibly easy to ignore. I'm amazed people bother to actually unsub artists for this. If livestreams are being posted more than once it means they DON'T HAVE VIEWERS, and big shock, reposting about it when someone new may be online might just have someone else pop in to visit them while they draw. If streams aren't your thing, I get it, but when you're a creator, connecting with your fans and viewers is amazingly easy through streams and makes a stronger fan/creator bond sometimes. If someone were to unsub an artist for daily stream notifications (I dunno maybe they do this for a LIVING and it's a nice way for them to stay focused and connect with viewers at the same time) that are easy to ignore, the only thing I can think is you weren't invested in their story at all in the first place. Because being invested in a story would mean you'd simply click the tab and move on and wait for the newest exciting plotpoint to be revealed, and that you genuinely care about the world and characters but just aren't interested in the streams.
If someone unsubbed me for something as trivial as a lil red notification number, I'd say good riddance since they couldn't be bothered to click the dropdown and move on, and then continue to stream for the folks who wanted to hang out. Because IMO that's petty.