Nowadays even YouTube comments are more anonymous than using a "deltachat" or "signal". On the first case there is zero verification on their claims, on the second case there is plenty of evidence of funding from the CIA.

At least commenting from an unknown account on any random youtube video won't land you immediately at a "Person of Interest" list and your comments will be ignored as a drop of water inside an ocean of comments.

It's been a while since I looked at it but as far as I know delta chat is just email so it's as anonymous as your email account I'd gather.