Your selected worst exchange, may best for others but it doesn’t matter. Share the name of exchange which gave you worst trading experience, scam your fund or sometime else. Share, so that others can alert from it.
Those exchanges which had scammed were not into business anymore. This is the common scenario. Scammy exchanges cannot sustain in this crypto space. With the power of this community, we can push scammy exchanges to get shut down hence obvious scams cannot continue their bad behaviors for long duration.
Even I appreciate your efforts for this discussion; I guess it would be a good practice to have the list of reputed exchanges rather than looking for list of worst exchanges. When you know 2 to 5 reputed exchanges, I am sure you can survive in this crypto space without any major problems.