Everything I ever added to Wikipedia was removed, within the day, by a very diligent and hard-working Wikipedia person.
Same. Even a single sentence with an easily verifiable fact. Reverted in seconds.
I'm sort of in the middle on this.
Some pages have somebody guarding the party line, anything that goes against that gets reverted. (How can putting an accurate link behind a piece of text be wrong??)
Pages without such guardians I've never had an issue.
Same. My experience with the “concept” of Wikipedia was very high until I had the “direct experience” of Wikipedia, and I realized that the encyclopedia of the commons may not have planned for me to be in the commons.