It is true that the Iowa was modernized. It is also true that even after its modernization it was an obsolete unit which could have been mostly replaced by lighter, more modern units with little loss of capability.
Actually, the navy didn't (and still doesn't have) a more effective artillery platform. Bullets are far cheaper than missiles and the Iowa can fire a LOT of them.
Hence 'mostly replaced' rather than 'entirely replaced.' However, I would point out that there is an ongoing debate as to whether or not that role is worth keeping battleships or battleship-like vessels around for, with many feeling that the greater accuracy of modern weapons can adequately replace the greater volume of fire offered by the battleships without necessitating the added expense of keeping battleships in the fleet or in the reserves. I would further add that it seems as though most or all other modern navies and states have decided that the role of heavy naval gunfire support is not sufficiently valuable to justify keeping battleships in the fleet.
You got a point, or you just love to nitpick?
You requested an example of a WWII aircraft equipped with 'complex electronics' and 'energy beams.' I gave you several examples. Granted, 'complex' is relative; certainly, the radars used at the time would no longer be considered advanced and would not use electronics which are complex by modern standards, but at the time, they were state-of-the-art.
Carriers do need (and always needed) more crew than another ship of similar size. This is a iron-clad fact. If anything, SS ships are carrier/battleship hybrids, having a lot of weapons and armor to boot, meaning they would require even MORE crew. After all, it does the job of two different ships.
While a carrier would have less crew for manning guns (since it has less of them) it would require a large air crew; vice-versa for the battleship.
You are insistent that this 'carriers require more crew than other ships of similar size and always will' belief you hold is factual, and yet you have offered little solid support for this belief, aside from a single comparison between a battleship which was 30 years older and considerably smaller than the carrier to which you compared it. Meanwhile, you ignore counterexamples showing that battleships and carriers which were contemporaries of one another and similar in physical size had crews of similar size. You ignore that modern cruisers have crew sizes which, if the crew size were scaled by tonnage to match the carrier, tend to place the cruiser crews at about the same size as the carrier crews.
Beyond that, you seem blind to the fact that there are other carriers in the world aside from the US Nimtiz-class carriers, several of which, such as the Russian carrier Admiral Kuznetsov, have crew sizes which fail to support your claim (at least, assuming the crew complements on Wikipedia are accurate). The USS Iowa was 887'3" in length and 108'2" in beam with a standard displacement of 45,000 tons, and as originally commissioned carried a crew of 2788 men (151 officers and 2637 enlisted, according to Wikipedia). The Russian carrier (sorry, "heavy aircraft-carrying cruiser") Admiral Kuznetzov has a crew complement of ~1700 men with an air wing of about ~650, and is listed as 1001' in overall length (890' at the waterline) and 236' in overall beam (115' at the waterline), with a displacement of 43,000 tons standard. Look, an example of a modern carrier which is larger than the battleship and has a smaller crew than the battleship originally carried; even with your ~1800 crew number for the modernized Iowa, it still doesn't have that much larger a crew. Or we can consider the British HMS Ark Royal (Audacious-class, 1955-1979; numbers given are from Wikipedia and are listed as 'as built,' though the ship was apparently enlarged significantly shortly before it was decommissioned), which was 804' in length and 112' in beam with a displacement of 36,800 tons, and carried 2640 men (including the air wing), which looks like it should scale rather nicely given that the crew of the HMS Ark Royal is ~95% that of the USS Iowa while the ship dimensions imply that the HMS Ark Royal is about ~94% the size of the USS Iowa (by the rather simplistic and likely not terribly accurate measure of multiplying the ship length by the ship beam).
I will also add that there are some sets of ships you could use as examples which might better suit your argument. For example, if we were to compare the British Invicible-class light aircraft carriers to the US Ticonderoga-class, we would see that the Ticonderogas have crews of about 400 men, a length of 567', a beam of 55', and a displacement of about 9,600 long tons at full load, while the Invincibles have crews of about 1000 men, a length of about 686', a beam of about 118', and a displacement of 22,000 tonnes (~21650 long tons); if you scale the Ticonderoga's crew up by the ratio of the ship lengths, the Ticonderoga crew becomes about 484 men for the scaled-up cruiser, while if you scale by the ratio of the beams you get a crew of about 858 men for the scaled-up cruiser; if you scale by the ratio of the bounding areas suggested by the length and beam dimensions, you get a crew of 1038 men for the scaled up cruiser; and if you scale by the ratio of the displacements you get a crew of 902 men for the scaled-up cruiser. Scaling by the ratio of the displacements or by the ratio of the length-beam products are probably more reasonable, but there is at least a logical path that can be followed for the beam-ratio and length-ratio scaling, and the length-ratio scaling suggests ~50% less crew for the scaled-up cruiser than the carrier would have (of course, the beam-ratio scaling suggests ~15% less crew and neither of the other scalings produce more than a 10% difference in crew size, and I rather suspect that the later two scaling methods are more likely to scale the cruiser to a similar size as the carrier than the former two methods are). Similarly, the length scaling and displacement scaling for the Russian Kirov-class battlecruiser to the Admiral Kuznetsov aircraft carrier's size could be used to argue for significant differences in the crew sizes, though the beam scaling and the length-beam product scaling suggest perhaps a ~10-15% differences in crew sizes.
