I really don't buy this argument. You already have to moderate submissions - what's an extra field? Sure, UGC is more opinionated but just don't add star ratings and anything that promotes gaming of system. Just let users expand the dataset with more information, it's almost never a bad idea - isn't that entire point of crowdsourcing datasets?
That is not a flag "is the crossing wheelchair accessible?".
It's user created picture or text. This can be any kind of content, abusive, regulated by law, spam, subjective for chat control "age verification" controls, copyrighted and so on.
Moderation is a hard topic. Only very small communities can do that well.
Absolutely, can be abused. But there can be thousands of reviews of a pizza place, with text, surprising languages, slang, pictures... But only one description.
Thanks for the laugh.
Sure, a 'description' or 'name' tag can contain something inappropriate (like a slur of defamation). If it has high impact, it'll be reverted quickly. If it has little impact, not a big deal. Many tools don't even show the 'description' tag
Pictures are a whole other level. You need to blur faces and license plates. What if someones house is photographed? How to detect inappropriate images? Should one study the laws of all countries? Even the freedom of panorama contains many differences between European countries, let alone privacy rights, ...