Pinterest is one of the most recommended tools when it comes to building collections for most things art related. I’ve taken a few courses on concept art/concept development and Pinterest has been in 90% of it.
It’s used to collect references and build mood boards.
So, while self hosted Pinterest is a nice idea, it does miss the powerful part of Pinterest which is its search and community. When I want to find roman armour or steampunk vibe architecture, I don’t even have to leave Pinterest most of the time because the collections I need to find are right there.