Are Underwater Ruins useful for anything?

I've been exploring a bunch of oceans, and have found an area with a large number of underwater ruins. Is there anything useful that can be done with this large area?

• Do drowned spawn more frequently in ruins? (They seem to be, but that could be observer bias on my part) [This would mean it would be a good spot for a drowned farm for instance]
• Do any other mobs spawn more frequently in/around ruins?

Note: I have read the Wiki for drowned and ocean ruins, and it doesn't say anything either way. And yes I"m aware that they contain treasure. I mean once the ruin has been looted is there anything useful to do with it?

Here are some of the useful features of underwater ruins:

• They contain loot chests.

• They often contain semi-rare materials like prismarine, sea lanterns, and magma blocks.

• If you're looking for monsters to hunt, ruins usually spawn with a few drowned in them.

• In Bedrock Edition only, you get the "Atlantis?" achievement for finding an underwater ruin.

See also: Underwater Ruins article on Minecraft Gamepedia.

About the most important part is loot chests buried within about 50% of the ruins. They contain buried treasure maps. These maps lead to a place where a chest is buried under a layer of material diggable with a shovel (dirt, sand, gravel). The buried treasure chest, among other loot, contains Heart of the Sea, which is the central component needed for crafting a Conduit - an underwater beacon-like device.

(sometimes - occasionally - the buried treasure chest won't spawn. Also, if you open a chest and see it's empty wait a couple seconds, the game sometimes takes a moment to spawn the actual loot.)