Why didn't the valar take care of 👁️Sauron?

Originally posted by Maedhros
This is the closest thing that I have found in the works of JRRT.
From Myths Transformed:

That's it. That is why Manwë left Sauron, to give him the opportunity to repent himself. Now regarding the Istari:

Men had to deal with Sauron, and the Valar send the Istari as guides to help them, but Sauron was a problem that the Men had to deal with.

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Exactly!!!That was a problem Men had to deal.Elves were leaving ME and it was a place where Men had to live.That's why they had to learn to survive and Sauron was,let's say it simplier,just a part of their educational program.