Why navies retain sail training ships

Why do modern navies still have sail training vessels?

They support leadership training, seamanship and diplomatic visits. Retaining an existing ship makes sense, while a navy starting from scratch should spend elsewhere.

Sail training develops leadership and understanding of the sea. An existing vessel can also attract visitors and favourable attention on diplomatic visits. Those benefits support retaining a ship already in service. For a navy starting from scratch, the recommendation is to spend elsewhere.