Why worn Town-class destroyers still mattered

How poor were the Town-class destroyers received through the destroyers-for-bases agreement?

They were old but useful: rapid refits made them workable submarine escorts while Britain waited for new construction.

The ships were not good modern destroyers. Their value lay in existing hulls that could be upgraded in fitting-out docks faster than replacements could be built. Used against submarines, they filled an urgent numerical gap during the ramp-up of British escort construction.