A sustainable fashion writer I follow linked to these today, and I think they're really cool...flats that convert into heels.

https://pashionfootwear.com

I'm really intrigued by this idea and wonder how stable they would feel. I like having a pair of 2-4" heels in my wardrobe for dressy occasions, but mine are fourteen years old and no longer in great shape. I've resisted replacing because of how seldom I wear them. If I could wear as flats and add heels on the rare occasion I need/want them that would be amazing.