Why are table's turning away from adobe flash player?

I have been looking around for an affordable tablet that can use adobe flash player but all I have seen does not support it anymore can someone tell me why?

Adobe stopped writing Flash for new devices about 2.5 years ago. You will have to ask them "why?", but the general feeling is it is very slow, eats batteries, is full of security loop holes and is not a good design for the modern web.

But if you are looking for an affordable tablet that supports it, you can't have looked too hard! Try: Dell venue pro 8 or Lenovo Miix 8 or Toshiba 8". They all run full Windows 8.1.

Adobe is turning away from supporting operating systems other than Windows.

The use of html5 is more efficient the flash

I think it's because it has continual security issues. Another of Adobe's software, Adobe Reader (pdf viewer) is the same way.