Adobe Flash format - Pain to download Why???

I have one basic question and pls guide. I am literally going crazy and feeling bad.

Why everyone on the web is using adobe flash format (thats what it is in my understanding). Its impossible to download and play.

Pls see link - DS GRC CC

and click on view demo.

DS GRC CC

Why all websites , companies, etc are using this format if its not easy to download?

How can we download and play? These are legal contents. Whats wrong?

Am I missing something...I have tried everything IDM, orbit etc but failed.

Pls explain the issue. WHy adobe flash player is such widely adopted?

Note: I am aware of adobe flash player and i am not talking about downloading adobe flash player. Rather how to download online vidoes such as in link above for offline viewing

< How can we download and play? These are legal contents. Whats wrong? >

It has nothing to do with the Flash format. The owner of the "legal contents" in any format chooses the usage of his/her property. In this case, one can view and rate the property only. Future viewing can be done at this site, if it's still available.