Well they do some of that: reconnaissance both electronic and visual, coastal bombardment (and air strikes) with cruise missiles, and they can land very small groups of special forces too. Not to the extent surface ships can but if suddenly something made surface warfare impossible, submarines could take over a chunk of it. And you can imagine easily how drones might be embarked on a submarine and launched like cruise missiles.

> coastal bombardment (and air strikes) with cruise missiles

Submarine-launched missiles, in a diverse navy, can launch from underwater. That's great for stealth. It's terrible for budget. A submarine-only fleet would need to surface to economically attempt coastal bombardment and air defence.

That said, I'm not sure what fraction of e.g. the U.S. Navy's submarine missiles are capable of subsurface dispatchment.