Have sites that have not already update themselves to playback swfs as a different format like webassembly. Ruffle.rs is commonly used for this. It is currently a work in progress and there are also several others doing more or less the same. The idea is it takes a flash file, loads it as webassembly, then plays it like normal with no loss of any kind. Since its played in webassebly it cant be saved properly anymore (far as I know) and the flash security issues that supposedly existed in the past are fixed this way. Also some swf should extend to mobile devices because of that. Im having issues using it with firefox though.