Barrier nets protected parked aircraft before angled decks

How did straight-deck carriers protect parked aircraft from landing accidents?

They used arresting barriers and multiple nets; angled decks would not eliminate every such accident.

Straight-deck carriers used arresting barriers and often more than one net. An aircraft had to miss the wires and penetrate those barriers before reaching parked aircraft. An angled deck would not necessarily solve every damaged-aircraft landing scenario.