Many venues, art-spaces and theaters have websites. There, they generate calendar data, but it's locked up. If opened to the public it would benefit both the organizations and the visitors.
Today we have limited options to stay up to date, mostly social media, newsletters and websites — all with different drawbacks, so this could be a complementary way.
Having this data available lowers the threshold for experimentation, so by contributing with your data, you are making a form of donation to a collective process.