I know the prevailing sentiment for a long time in the privacy community has been "DAE Youtube bad?" though I have always thought that it is kinda overblown. Besides, I am using Firefox which is supposed to isolate tabs so they can't speak to each other, so I felt a small amount safer using Youtube.
You can take my post with a grain of salt since all I have are anecdotes, but can anyone else confirm encountering creepiness similar to my experiences:
-Typing anything in another window that is not my browser, sometimes these words seem like they get picked up by the Youtube suggestion algo and then boom, I get suggested videos based off of those keywords. Recent example, I was copypasting the words "trans" and "talking" over and over for some nerd spreadsheet I am making (read: not transgender purposes) and what do you know, transgender videos about "How to change your voice" start popping up in my feed. Please know I have zero interest in transgender politics/culture/anything, it is not something I have ever searched for or engaged in online. Possible that Youtube is reading my clipboard? Reading my keystrokes?
-Listening to an album via VLC, while Youtube is open in my browser. Suddenly, more tracks from that album start showing up in my suggested feed. Possible Youtube is reading the titles of other apps current open on my machine? (VLC changes its active title to the name of whatever file is currently open)
-Have a Discord channel open in another tab, people there start posting things I am uninterested in and don't click on, but lo and behold, videos related to those things start appearing my feed. Tbh, I am the most jaded about Discord's privacy security because there is probably a direct communications pipeline between the Discord and Youtube where they link accounts to each other, even creating shadow accounts similar to how Facebook does. So while not surprising... still at least a little bit creepy, yes?
edit: let me add a small bit of context. I use Youtube all the time as my personal version of Spotify. Adblock+Youtube still works for me and is very nice. So all of my Youtube video suggestions are always music related. If anything weird shows up in that feed (you know, not music-related stuff) it sticks out to me immediately.
edit2: thanks for the replies, even if you are disagreeing with me. I promise you I am not the person downvoting everyone lol.
I think I can explain some of the "inexplicable creepy" moments you mention here. Note that I'm not advocating for YouTube's favor; I'm just explaining how things tend to work in general.
Your spreadsheet seems to contain two key words or terms that are trending in the current year/week/month/day in your area. I wouldn't be too creeped out about this, it's just a lucky guess; Firefox cannot access your clipboard history, nor does it allow websites to do so. Furthermore websites cannot read your clipboard unless you have them focused as the active window and you click on a text field in that web page. Once again Firefox here is protecting you and most browsers behave the same way anyways. They don't get data about clipboard contents at all until they're focused. CAVEAT: If you were using Google Sheets or a spreadsheet application ONLINE that IS IN YOUR BROWSER then we have a different story. For sake of simplicity I assume you are using something like LibreOffice Calc or Microsoft Excel.
Second verse, same as the first! Your musical tastes are probably highly similar to many people in your vicinity and Google is using that to suggest content to you. This can even get spookily accurate if it even only knows your gender and age range based on what you watch. RECOMMENDATION: Clear your Watch History and keep it Paused.
Discord actually does load the video embed / information from the YouTube API. But unless you're living in SF; this is not linking back to you unless you are clicking on those videos at all. However, if you are loading Discord in your Browser; YouTube might be able to make some weird fingerprinting connections. The solution is simple: Download Discord Desktop and install it...or if you don't like Discord software you can always use Beeper ( https://www.beeper.com/ ) which is slightly more privacy preserving, but has limitations. Alternately you can isolate Discord tabs to a Private Window.
Or isolate discord with a tab container in Firefox. Invidious is still preferable though.