Even the makers of Flash argue against splash pages on websites!
miniblog.
Related Posts
Archiving Flash content before the plugin dies and the websites disappear forever:
https://blog.usejournal.com/adobe-flashs-gaming-legacy-thousands-upon-thousands-of-titles-and-my-efforts-to-save-it-58c14811558a
(Though there's still a need to preserve content using platforms that aren't about to die, the demise of Flash has spurred this project.)
Tracking Flash's decline with Stack Overflow question trends, and looking at tech with similar trends: https://stackoverflow.blog/2017/08/01/flash-dead-technologies-might-next/
Good end-to-end crypto is important, but every time I update my system there are RCE fixes (browser, flash, etc). The ends aren't secure!