Your suggestion is good.
But google Maps is a worldwide platform and system.
They Choose that thing that cover all criteria from the world…
Street art is mainly popular but it’s not popular in India and other country… So I think that matter google Maps not add this.
Ya, we add this in Subcategory of attractions. …
Also check my post that get you idea…
https://www.localguidesconnect.com/t5/Idea-Exchange/Add-NGO-category-in-Google-Maps/idi-p/2334906
Thanks…