This resonated with me. It's almost impossible to predict which creative acts end up being "important" or "meaningful". I've tried to make "important" things that felt like total duds, and I've made nonsense that felt very important/memorable/meaningful/whatever.
Personally, I've found it's better to shift my focus towards making something that is sincere or honest as opposed to "important" (a term that is far too vague and fickle). For example, I've read plenty of manifestos in this jam that I think were trying very hard to sound "important", but failed to really connect with me. I think your manifesto served as a gentle reminder that sincerity and honesty is what I connect with most, and that "importance" doesn't really matter all that much.