The reason there is no trade market for Trent Williams is that the Redskins so far have reached out with the supposed intention of bringing him back.
I don't think I have seen any report where he is being actively shopped, although his most recent comments about a contract at the top of the OT market might result in his being traded near or at the time of the draft.
The truth is Williams received the largest OT contract in NFL history on his current deal and per his request that money was heavily front-loaded. Now he is complaining there isn't much left on the back end.
Well, that's the consequence of getting what he wanted in the beginning.
I am in favor of guaranteeing him his 2020 salary at this point and adding on an extra guaranteed year perhaps with an option.
But not at $18M. He's 32 years old and at an age where NFL players outside of quarterbacks are usually at the back end of their primes.