If you truly want the plushest ride known to man, look at a 2017 to 2019 Buick Lacrosse. We test drove one a few months back and it was the nicest riding car I've ever been in! It's a shame GM killed it. You can find them relatively affordable with lower miles still. If I wasn't so stingy, I'd run out and drop 20k on one with less than 30k miles and have tons of smiles per mile on road trips. The trunk is huge as well.
We owners of the last gen Park Avenues (ended in ‘05), call newer Buicks “sports cars” for their comparatively stiff ride.
Your point is well taKen, however, “don’t send a truck to do a car’s job” when it comes to comfort.