The importance of 'boats for all' has long been exaggerated when big passenger ships are considered. There are plenty of cases where people on small ships have been saved by the ship's own boats, but when we talk really big numbers we find few examples. The only case I know of in which more than 1,000 people have been saved by a ship's own boats, without outside assistance, occurred in 1999. The cruise ship Sun Vista caught fire off the Malaysian coast. When it was decided that the fire could not be controlled, everybody took to the boats and liferafts. The total saved was 1,093. The ship later sank and the people were picked up by a number of ships. The incident took place in warm weather and duckpond conditions. Whether the singing of My Heart Will Go On helped is debatable. The story is probably still on the BBC news site.
I'm talking here about peacetime accidents, but I doubt that in war there has been a case in which more than 1,000 were saved by their ship's own boats, without assistance.
You may be surprised to know that there has never been a law unambiguously requiring 'boats for all'. It has always been permissible to use a mixture of boats and liferafts and many cruise ships do. They typically have enough room in the boats for all the passengers, plus a few crew. The rest of the crew use liferafts.