Firefox still supports Adobe Flash, however, all versions currently in the wild have serious security holes that are actively being used to spread malware. Firefox has blocked all of them. You can check for new versions of flash at https://get.adobe.com/flashplayer/

If Firefox is blocking "unsafe" Adobe, why would I want to continue to use them?

If you frequently use a website that requires Flash. If you don't then feel free to uninstall it

any other players out there besides Adobe?

Not currently, no. Many website are moving away from Flash to HTML5 video, which is better for the web and for you (https://www.youtube.com/html5 for the biggest example of an HTML5 website), but there is no alternative to playing Flash videos at the moment.