Blueprints gets used because the only alternative in UE, writing decade-old paradigm C++ code with 2 decades old macro DSL on top of it, is a lot worse.

Unity has had multiple visual programming packages and people don't really care. Writing 2017 era C# paradigm code with an API resembling 2004 Macromedia Flash is not nearly as bad.

> Unity has had multiple visual programming packages and people don't really care.

People cared enough for Unity to buy one and make it official but Unity doesn't care so it mostly just rots.

Its important to note that some successful Unity games were still made with visual scripting tools e.g. Hollow Knight used Playmaker.