What was left by those before, still standing and still depended on. Legacy is not a fault; it is evidence something worked long enough to matter.
Latin legare (to bequeath, appoint by will, send as ambassador), from lex (law); what was formally left by those before, still standing because it was made to last.
Not a fault but evidence — a thing still standing because it worked long enough for something else to come to depend on it.