They can serve the purpose of evacuation. In 2006 the USS Iwo Jima (one of the ships now going there) evacuated US citizens from Lebanon. USS Iwo Jima is part of the 24th Marine Expeditionary Unit. Yes they do evacuations. I’d rather be evacuated by a warship than anything else,
I rather fly out. Ships would be fine but they are combatants and would be considered targets.