Cross-platform GUI Toolkit Trainwreck --- 2016 Edition

Ok, I’m not too sure in what direction this post will go, an informative article, a rant, or both. Probably a bit of both, with an emphasis on the rant part, given my current not-quite-positive emotional involvement with the topic. Gentlemen (and gentlewomen), please fasten your seatbelts!
UPDATE #1: It turned out to be a quite informative mega-post in the end, just don’t give up reading after the first section…