[szszrk]

> what's an extra field?

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.

[fizwidget]

To be fair there are examples of freeform text tags in OpenStreetMap already, e.g. “description”.

[szszrk]

Which is hard to get to, doesn't even render on some apps at all, it's easier to automatically or manually moderate as it has a more defined purpose and it's pure text (not meant for personal feelings towards the place, not meant for rating etc).

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.