I saw the retirement of the USCG lightships in the early 1970s. In fact the Lightship
Nantucket was the last one in service.

Lightship duty was long periods of boredom relieved by minutes of utter terror. The Merchant ships all had radars, automated controls,and minimum crews, and in theory there was always somebody on the bridge to avoid collisions. But Otto was steering almost always, and the USCG Lightship was anchored right at the entrance to the Boston channel reserved for large ships. As a tanker or container ship bears down on your lightship, you blast the air horn, hoping to wake up the crew of the merchant vessel. You also started the diesel engine, hoping you could throttle up and drop the anchor chain and dodge the oncoming ship. All too often, the lightship would be cut in half and sink with all hands. This happened to the LV-117
Nantucket on January 6, 1934, when she was cut in half by the
HMS Olympic, the sister ship of
HMS Titanic.
Finally 1970's tech including GPS enabled the construction of a station-keeping buoy that replaced the
Nantucket on that most difficult duty station. It was anchored, but when the anchor dragged, it would raise anchor, start it's engine, and return to station.
Station-keeping buoys are still lost in collisions, but at least they are unmanned.
Newfie, the
USS Fitzgerald is an original Arleigh Burke class destroyer, costing about $1.5B after all the technology upgrades. The two surface search radars do not cost "billions", they total about $4M, peanuts compared to the SPY antiaircraft radar array, or the sonars used for anti-submarine warfare. The surface-search radars are variants of commercial systems, it is even possible that the container ship had the same electronics.