In figjam especially people commonly sketch out diagrams with lots of freeform lines used as arrows to point to things, sometimes as they talk about them (both when brainstorming and when annotating). It would be a really nifty feature for advanced users to be able to automatically have a line get converted into an arrow. Could also see this relevant in Figma too.
I think everyone can maybe relate to the pain-point of having to either go into the setting to choose the arrow end-style for a line you just drew (a little finnickey and breaks flow if drawing to explain something on a screen-share) or else you manually draw the tip of the arrow each time for each line (doesn’t look good and if you want to move the arrow you have to select both the arrow tip you drew and the line itself)