The Mysterious Golden Cities ! At least the first season, I’m not too sure about the directions it took after that, when it became 3D animated… Then, Ewilan’s Quest ! I don’t think there’s an official translation or a legal way to watch it outside of France for now, but if you put it at the end of your list there might be one by the time you get to it.

If we exclude Musk, no, it’s not worse than Instagram. Musk is a pretty big deal tho. Now, the Zucc is pretty evil too, so anyway I’d say Instagram and Facebook are fair contenders for worst platform.

Personally I deleted Twitter as soon as the purchase by Elongated Muskrat was confirmed. I deleted Facebook and Instagram more recently (I hesitated longer because I was using it more to communicate with irl acquaintances). I still use WhatsApp, until I can get some people I need to keep in contact with to start using Signal or Telegram (I know I’m not gonna get them on Matrix or xmpp, not worth trying), but it’s also owned by the Zucc so it bothers me to keep using it.

If you mean as the artist, just work in high resolution in the first place.

If you mean using AI upscaling on someone else’s webcomic that’s already been shared several times and lost quality along the way before reposting, that’s because it can cause aberrations and sometimes looks uglier than a low quality webcomic. Better to reverse-search it with tineye to find the original, which should be in good quality.