For OOP languages, you can definitely get IDE plugins, which create UML from code.

Personally, I've never found them useful, though, partially because our code was never OOP enough, e.g. we were using the actor pattern, or had important modules with functions, or had lots of small classes for handing data around etc..

But also because it just makes for bad architecture diagrams.
It has no sense of what's important and what should be abstracted away. Or how to structure the diagram to make it readable, e.g. REST API at the top, database at the bottom.

What I also really don't like about generated architecture diagrams in general (even when the contents are specified via e.g. PlantUML), is that things jump around every time you make a structural change. This means people looking at the diagram have no chance of learning what it looks like, so they can spot changes or know where to look for what they're interested in.