The German and Italian planes in Rome can hit Z98 and land in Greece, Tobruk, or Libya, so your ships are not safe there…even bombers from West Germany can reach. If you do Taranto, your planes can land in Malta, where they’re safe, and then in Egypt next turn, so they’re not really out of play. You usually lose a destroyer, 2 cruisers, a fighter, and the carrier (TUV 58) in exchange for the Italian 2 transports, destroyer, cruiser, and battleship (TUV 54). You’ll likely kill a German plane when they counterattack, making the TUV trade favorable.
The strat bomber from London can’t quite reach Tobruk.
If you turtle in Z98 with destroyer, cruiser, carrier, 2 fighters, and a tac for scramble, the Italians can hit with with their sub, destroyer, 2 cruisers, battleship, 2 fighters, and strat bomber and easily destroy it. Yes, the French fleet will stay alive, but Germany can kill it if it stays in the Med.