That’s exactly what you think going in...that’s the point I’m making.
No one is hand rolling drag and drop these days.
There’s a lot of complexity implementing drag and drop both visually and binding stuff to events. It’s messy and finicky. Unless your usecase is very simple.
To add to sibling's point, many drag-drop libraries work great on a bare demo website with nothing else to worry about.
Once you start trying to add it to your frontend with other complex features already there, you're back having to reason about the core of drag-and-drop and essentially solving it yourself to parse the library's code. In my experience I've had to modify library code to handle my requirements most of the time because it did not play well in a complex environment.