Why large wartime merchant ships rarely survive as museums

Have any large Second World War merchant ships been preserved in the United Kingdom?

No large example comes to mind. Merchant ships are repeatedly resold across companies and countries until no original owner remains to preserve them.

No large preserved British example comes to mind, although smaller survivors remain. Merchant ships tend to pass from one company and flag to another throughout their working lives, reaching scrapping under later owners in other countries. That commercial mobility leaves no single navy, state, or original operator with a continuous institutional reason to preserve the vessel.