This is certainly true of the historical battleships which were massively armored behemoths, boasting turrets with 20 inch guns.

Quibble: 16" guns.

Yes, obsolete because they only have ~24 mile range. When built, that was tremendous. Now, anti-ship missiles (air or sea launched) can reach out and touch a ship from far beyond that range.

I went and looked up the proposal. It's already got a wiki page. From this image, I agree it appears to be a large destroyer, or possibly a heavy cruiser. I would like the rail gun idea if it worked. However, the Navy has given up (mostly) on the rail gun because of integration and durability issues; preferring laser development. Which is probably more practical for counter-drone (maybe as an augment to Sea Whiz). Reading the wiki, it is proposed to have multiple lasers.

en.wikipedia.org - Trump class battleship

I note it has a very British name. We usually name our ships after cities, states, and dead people. The Brits usually name their ships with adjectives (e.g. Indomitable, Courageous, etc). Not a hard-and-fast rule (e.g. British HMS Hood, US Intrepid). But it mostly holds.

An Arleigh-Burke has 96 Mk41 VLS cells. This thing is calling out 128. It is bigger than an Arleigh-Burke (35K tons vs about 9900 tons), and is designated "BBG" which is "guided missile battleship". Aegis, obviously. For comparison, Iowa class was ~57K tons. Not much detail about survivability (armor). Just eye-balling it, it looks like a Kirov class equivalent.

So, it really isn't a big-barrel battleship. The VLS cells make it relevant to today's Navy. They'll probably have to ditch the rail gun. For its size, it doesn't have that many more VLS cells than an Arleigh-Burke. It has a decent top speed, assuming this becomes a reality.

Just first impressions. As I have time, I may dig up some more on it. The Navy needs new ships, and at first glance this isn't a hopeless boondoggle. Though, my first reaction is "we need a new destroyer class, and this ain't a destroyer".