Is it possible to write a graphics editor in Unity or Ureal Engine?

Question

User interface

Is it possible to make something like a lite version of Sketch, Photoshop I'm
interested in the complexity of implementing the following requirements:
- drawing basic geometric shapes
- drag'n'drop, object transformation
- import and display of .svg, .jpg and other images
- export of the resulting composition to format .jpg, .png
- saving the project to a file of its own format
- drawing interactive ui components: inputs, lists, trees, etc.

Answer 1

Maybe. Just like removing tonsils through the anus.
There are tools for everything. A graphics engine is not the best tool for writing a graphics editor.