ICAEW's guidance is blunt about where the going-concern assessment lives: with the directors. Management must form its own judgment that the company can continue for the foreseeable future, supported by forecasts and sensitivity to plausible setbacks; the auditor then evaluates that judgment, not the other way round.
In owner-managed companies the assessment often exists only in the owner's head. Writing it down once a year, a cash forecast, the key assumptions, what breaks it and what the fallback is, costs an afternoon. It sharpens decisions in good years and becomes indispensable the moment financing, a big customer or a shareholder asks hard questions.