Taking one carrier out of service is much easier with a larger force than after two major losses. Extra decks create room for maintenance, training, and force rotation across many theatres. With eight usable flight decks, a temporary refit leaves seven; after losing the sisters, the same decision can reduce the available force to five. Their survival would therefore improve the condition of other carriers by making timely maintenance and modernization easier to schedule.
Notable Point · 57:46-59:55
Why two early carrier losses constrained every refit
Keeping the sisters afloat would make temporary modernisation practical by leaving the Royal Navy with enough flight decks to cover its commitments.