I might be an unusual case, but when I present graphs/charts it's not usually because I'm trying to point something out. It's usually a "here's some data, what conclusions do you draw from this?" and hopefully a discussion will follow. Example from recently: "Here is a recent survey of adults in the US and their religious identification, church attendance levels, self-reported "spirituality" level, etc. What do you think is happening?"

Would love to hear a good example of alt text for something like that where the data isn't necessarily clear and I also don't want to do any interpreting of the data lest I influence the person's opinion.