Hard to get even tension with a dished twist lace, and it's less durable than a 2 or 3x wheel cus of all the stresses going on all over the place with the spokes, rims because of those harsh angles, and the more you twist those angles get more severe. Did I mention, they absolutely suck to build?
runninboy boy got it right in his first few words, the key one being "novelty", that's all these are. Many builders still do it, but serves no practical functional purpose other than to be interesting looking. Training wheels, absolutely not.