Quite interesting if you think about it! A bit of an antithesis to the idea that what's on the web is preserved forever.
I struggle to see how doing so would harm them commercially. Even if an open source player is available, browser vendors have no interest in supporting it, so it won't be supported with browsers. It isn't going to take away interest in their newer pure HTML5 authoring tools.
Looks like it got dropped from Ubuntu though.
Basically there is a program you can download from Adobe called Flash Player Projector Content Debugger, then you just point that at the .swf and go.
An open source emulator would be better in the long term, but for now this is easier than trying to find a browser that still supports Flash natively.
• Windows: https://fpdownload.macromedia.com/pub/flashplayer/updaters/3...
• Mac: https://fpdownload.macromedia.com/pub/flashplayer/updaters/3...
• Linux: https://fpdownload.macromedia.com/pub/flashplayer/updaters/3...
Download the version for your platform and open the swf file you want to run. That's it.
Linux users can also use the community-packaged Flatpak: https://flathub.org/apps/details/com.adobe.Flash-Player-Proj... All other links come from https://www.adobe.com/support/flashplayer/debug_downloads.ht...
Now that the adtech firms switched to building the browser and the cluster of html5 technologies have matured it's easier to track people natively. That's really the only reason flash went away.