However, if you are a web developer and you publish a page created in Flash it had one major advantage. The SWF file could not be copied and changed by other developers and the editable file (the FLA file) would not be uploaded online, thus protecting your work. Currently, if you right click on a website and copy the code (plus the files linked to in the code) you can copy the front end of a website very easily.
I remember using ActionScript 3 in Flash and you could still update the content of a Flash website using an RSS feed and this is still a supported file type. The technology was years ahead of the alternatives, and if it had kept evolving it would also have made the web less generic.
Also, with most websites having a specific mobile version, I believe the technology could have had a future, even if a more restricted one. I always liked how individual Flash Banners could be on a website and with HTML5 I believe they look good but normally quite similar. I don't think Flash will have a resurgence but I do think it was a great technology that made the web visually interesting.