It's official: Flash is dead. Adobe is now blocking content made with Flash from running on browsers.
On Flash's final update page, the company stated, "Since Adobe will no longer be supporting Flash Player after December 31, 2020, and Adobe will block Flash content from running in Flash Player beginning January 12, 2021, Adobe strongly recommends all users immediately uninstall Flash Player to help protect their systems."
It's more accurate to say Flash has been dead since Adobe's announcement for the tool's end-of-life plans in 2017. And before that, Flash certainly was well on its way to the grave. Not a lot of websites were still using it, and HTML/CSS became pretty much the new tool kit. iOS devices also stopped officially supporting Flash, circa 2010. Steve Jobs famously hated Flash and wrote an open letter criticizing the plug-in for its reliability and security, among other things.
But in its heyday, people used Flash to make websites like really popular websites--and DIY novelty games, as explored in writing like Nathalie Lawhead's Short History of Flash and The Death of 2 Advanced.
Not all was good, of course. Adobe made the decision to kill off Flash in part because of its security issues. Flash's security holes provided the throughway for multiple attacks against desktops.