Why Flash and its Scripting Language had died in the web market?

if you still using IE7,8  then i recomend you to use flash and actionscript  but for the flash is not supported in windowshpone and is heavy for use on these smartphones that is a point of opinion and the facts now a days the html5 is taking a slow replacement of it despite the fast page load while you use the html5 because it is a built in feature not a plugin like flash player 

despite that they thought that adobe air well replace the adobe flash but the problem is with the end user and how to keep update the adobe air agent or flash player which now google chrome and Firefox have many problem with adding the flash player and google tried to install it with google chrome as a package but it still take a big amount of processing  and memory

now we are living in a technology area who is looking for minimum requirement and massive speed  and that in the end user part taking to the server side the bandwidth matter it is costly on the server owners  especially who use self hosted or vps so i recommend you to take a step towards the html5