It's changing and when you say most phones are flash enabled they are not. It's the browser in which you use to view a website needs to have the flash plugin installed and compatible to the browser or some browsers now have it built in. Just look in the app store.
I don't like installing a plugin just to view a website with all the non-sense malware that is out. If I were a pontential client and visit your site and I have to add something to view the site , I will move on and go elsewhere.
Flash is out the door , but great for video streaming and has been fastastic since Macromedia created it.
But anyway for a personal or business website in my opinion use html 5 and css 3 (Standard now) . All updated browsers see this , it's responsive and will adapt to any device screens size and very interactive. And best of all it's amazingly fast.
If its a personal website or even business. I strongly suggest to make this easier use a content mamangement system. WORDPRESS or Joomla are my two favorites and free in a sense. It's much easier and reliable and so far IOS and Droid pull the website perfectly.
I know this is old and I am sorry . I'm just playing with scripts and adding content. I know people will agree with me on this.
But you are correct in my opinion.