Can one trace the bitcoins to the end
There's a core of truth in your question. Indeed, eventually it will reach a point where you can trace it. But there might have been a lot of transactions/hops before that happens.

If it has switched that many hands, how can you be sure that it is still in the hands of the cybercriminals? The money might have been yours but it has been used in quite a few legit transactions. On top of that, finding out the identity of the last person doesn't help in catching the bad guy.