The only obvious problem on a quick look is that it's completely lacking in any filter components.It's designed for 220V operation.
It's on Electronics Lab which means there's a good chance it's full of errors and will fail.
Horses for courses. Most of this circuit was likely lifted from a mass-manufactured mains-powered product, where cost savings have to be made to stay competitive, or else fall by the wayside. No consumer wants to pay more for a product if there's a cheaper sold one elsewhere that does the same job, consumer isn't impressed by things he doesn't know or care about. I've seen these transformerless non-isolated power supplies often, this is about average for them.circuit is good enough for the trashcan.