On the computer, Flash is responsible for many crash errors (Flash ads now still crash Chrome). When the Internet grows with Flash, it becomes the object of hackers and malware. 'Flash security vulnerability' has become a hot title for more than 15 years.
Initially, HTML5 was something that threatened Flash's dominance, especially with videos. YouTube started supporting HTML5 video in 2010 and switched to HTML5 completely from 2015. That change has affected Flash, but it's the mobile devices and the culture that depends on our application is the blow. decided to kill Flash.
In early 2010, there were 10 thousand applications (and now more than 2 million applications on the App Store), but there are still no Snapchat or Instagram. Many people still use Twitter on the web and like others, Mark Zuckerberg has been convinced that HTML5 is the future of mobile applications. By 2012, Zuckerberg admitted betting with HTML5 is a mistake.
We spend a lot of time watching content and videos on Facebook, Twitter, Instagram, and Snapchat, which means not watching ads on traditional sites, which are where Flash is used. Advertisers are no longer relying on website visits. It means that fewer and fewer people use ads the old way with Flash. Obviously when Flash officially left in 2020, many old websites will also use new advertising tools.
Flash as well as Western Union's telegraph service, was useful in the past, but now too old. Although many people believe that Flash security is weak, it must be acknowledged that the web will not be available today without it. By helping build the Internet, we will not forget to have Flash.