Thirty years is about the useful life of a ship. They start deteriorating from the moment they go into the water. Rust, time, use, heavy seas all take their toll. At some point it costs a huge amount to keep the ship at all. It’s better to just buy a new one, with all the latest tech and stealthiness built in.
We could still be using WWII ships, but imagine the upkeep and in the end, you’d still have a ship that was past its best-by around 1975.
It was a shame, as that was my home for three years.