Flash, from the very beginning, was a transitional technology. It was a language that compiled into a binary executable. This made it consistent and performant, but was in conflict with how most of the web works. It was designed for a desktop world which wasn’t compatible with the emerging mobile web. Perhaps most importantly, it was developed by a single company. This allowed it to evolve more quickly for awhile, but goes against the very spirit of the entire internet. Long-term, we never want single companies — no matter who they may be — controlling the very building blocks of the web.