From the article:
In a public letter in 2010, late Apple CEO Steve Jobs criticized Flash's reliability, security and performance. Since then, other technologies like HTML5 have emerged as alternatives to Flash. But Flash’s popularity began to wane after Apple’s decision not to support it on the iPhone.
“This trend reveals that sites are migrating to open web technologies, which are faster and more power-efficient than Flash,” Google said. “They’re also more secure."
Adobe tells developers to use HTML5 instead of Flash | InfoWorld
Adobe renamed Flash Professional to Adobe Animate CC. Adobe already offers slew of stand-alone HTML5 design and development tools under the Edge brand.