As a photographer, I can see how you’d think that, and normally you’d be right, but you do not own the copyright of an image that faithfully reproduces a previous image. That is the precedence set by Bridgeman Art Library v. Corel Corp.
In order for new copyright to exist for a derivative work, the new work has to add something new that isn’t in the original. A reproduction does not do that. Their photos of furniture and sculpture and any other three-dimensional objects would be their copyright, of course, as the choice of angle, lighting, etc constitutes originality, but not the reproductions of two-dimensional work.
And I do now see that there are also non-PD images available, but they are clearly marked as such.
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.