Follow the link in GP.
Also explains why the ads in the copycat version didn't integrate at all with playback controls or the rest of the app: Someone probably took the original apk, slapped the ads on as a separate thread/process inside the apk and never modified the app's original source.
This literally is browser history. Your browser is already giving you this.
My suggestion is to stop worrying about hypothetical privacy problems and just use the watch history feature. Google will even automatically clear old history for you if you want.
HN nerds get the worst user experiences because they have these random lines in the sand. I’ve been guilty and often try to break out of it when I realize that the people who don’t know better are enjoying themselves more.
They eventually started trickling in suggestions based on watch history and today that's most of the feed.
I can see the argument that not having watch history means they shouldn't be building the per-user dataset to feed into the model to get the history based suggestions. Sure, but then... why not use the subscriptions, the information that users have provided you and what they thought that feature was for?
it's not weird if you examine it from the point of view of user retention metrics.
A subscription recommendation runs out, since you have small number of subscriptions (compared to the whole of youtube). Google wants to keep you clicking, and watching the next video. Algorithmically recommending videos instead of your subscription means you now have effectively infinite list of videos to watch, keeping your eyeball youtube.
If you watch videos on your laptop or your non-Android phone, invidious is quite good. I self host but I believe you could use any public instance and create an account there if you are fine with this public instance having your history and subscription list (which are separate from those you have on YouTube itself).
I.e., I would actually love to have a list of the videos I've watched recently - on my device, with a simple option to delete it, exactly the same way that browser histories have worked since forever.
However, with YouTube, it's all or nothing: Either, I let them track my viewing history globally across all devices, store it on their servers for all eternity and do who knows what with the data - or I don't get any history at all, to the point where when I restart the app, it will completely forget the video I just watched a second ago.