I don't envy the Dev's tasks on this feature. Its a very fuzzy line to know what to cater for if such a feature were to be added. However, several other formats can be imported and exported. Scalable Vector Graphics (SVG) is Inkscape’s primary vector graphical format. I'm surprised that, considering the multitude of uses arrows have, nobody has ever made an arrow plugin. Inkscape is a free and open-source vector graphics editor it allows creating or editing of vector graphics, including illustrations, diagrams, line arts, charts, logos, and complex images. I suppose the dictator is 'intended purpose' If you are creating a diagram that requires displayed measurements then a measurements tool would be a great feature, but we are heading into CAD and CAD features, Hot Doors CadTools for Illustrator are an excellent example for this type of work, if the arrow/s are for pointing or highlighting with notes then it's more about presentations. True, but as a one or two of, I think its an acceptable method. The pain factor goes way up if you need to change the curvature of the path. Also, unless you zoom in enough, it is all to easy to mis-align that shape & not notice that until later, after you have done some edits. It is still a PITA to have to adjust the position & rotation of the triangle shape at the end of a curved path to get acceptable looking results.

Inkscape arrow shape