1) "over 2 years" contains exactly that word: "YEARS". 2) It isn't all that long?? In software development that's ages!
For all who still expect the arrowhead feature to come soon, just a little reminder: actually, it has been on the road map from the very beginning in Aug 2014
and it still hasn't been implemented.
Last month, the company I'm working at, decided with heavy heart to go with Adobe Illustrator for another 2 years, instead of switching to an alternative like Affinity (like it was planned). In the case of Affinity we just came to the conclusion that it seems to be made more for artists (mangas, illustrations, etc.; see screenshots on homepage) than for designers/publishers who also need to create charts, presentations, etc. - for which that boring stuff (like arrowheads) is essential.