I've never sailed Viking, but I am on their mailing list probably because I travel a lot. Every year they put out brochures showing half off cruises if you book by a certain date. If this is the case for as many years as I can remember, and they sell out their cruises early this way, it's not the real price. But what it is is amazing marketing.
And to me, the sticker price on the new World Cruise is astounding. I am sure you can afford it, but frankly most on this forum and generally most people on the planet cannot afford it. And even if they could afford it, they might spend $100K for travel in a different way. I am sure you could not talk the price down more for this cruise because they have a set of perks built in and besides that, they can sell it to capacity for this price. They don't need everyone to spring for this deal, just enough to fill the ship.
Where the cruise deals are is on ships that will likely not come close to filling. When you see people offered deep discounts or even free offers, those ships and cabins leave the port with or without capacity. Getting some money for the cabin is better than no money for the cabin.
So where you and I differ on philosophy is that if I were given $100K and had to spend it on cruises, I would spend years piecing together cheaper great deal cruises for many, many trips, not on one. And I would use my points and miles for cheap or free flights to and from the ports. What you are doing is efficient and is a trip of a lifetime for sure. But I see cheap cruises leaving ports every day and I am afraid even if I had the money I am too much of a bargain hunter to cough up the large amount on one trip. A lot of people on this forum spend pennies on the dollar for their travel and will have a hard time relating to your situation.