Why can't the forsaken simply create Angreal's, Ter'angreals and Sa'angreals for their needs?

From what i recall they we're pretty powerful Aes Sedais in the age of legends where Angreal's, Ter'angreals and Sa'angreals were plentiful.

 

Elayne can make Ter'angreals and have taught other Aes Sedais how to make them so the issue of not knowing shouldn't be a problem...

Because making Ter'angreal is a very rare Talent apparently - of all the hundreds of rebel Aes Sedai, only 3 showed any aptitude for it when Elayne showed them. Most probably none of the Forsaken has this Talent.

Only 3? Ah ok i seemed to recall more, don't have the books on me :(

Here's the quote:

 

CoT, Ch. 17

 

She had been extremely disappointed when she could not learn to make ter’angreal — only three sisters aside from Elayne had managed that, so far, with very spotty success