The whole point of public domain is that others can use it as they wish--including to make money. I doubt there's a big business in selling only public domain works except as perhaps a more curated and easier to use experience. But it certainly makes sense to sell quality public domain works as part of a larger catalog.
Sounds like Getty et al would be providing a valuable service in that case.
Fortunately, in many cases, organizations like the (in the US) the Library of Congress and non-profits like the Internet Archive do. But no one is required to do so. (Aside from some legal mandates in the case of the LoC.)
What valuable service? they are extortionists - https://onehourprofessor.com/getty-images-demand-letter-gett...
And what does reselling the work itself mean? If I sell a picture book of Colorado that combines these photos with some maps and long captions, is that reselling the work? How about selling prints? That's a value-add service.
For all of its faults, one of the advantages conveyed by private property ownership is in creating an interest in that property.
The commons, whether real property or virtual as in the case of intellectual works, has no such protections, and there are relatively few institutions which seek to protect and defend it.
In cultural space we do have works which have been passed down through the ages, though many of those come through particularly long-lived institutions, most especially religious (the canonical texts of Judaism, Christianity, Islam, Hinduism, Buddhism, Taoism, Confucianism, the Greek and Roman mythologies, etc.), but also educational (often tightly coupled with religious institutions), and more recently scientific organisations (again, often coupled with educational institutions, both religious and secular).
There are the traditions of libraries and museums as well.
And there are many instances in which cultural commons have been appropriated by commercial interests, the case of Disney being particularly prominent.
I think that raising the question of what institutions might serve to curate, shepherd, and defend common works, how those might be structured and organised, and what models serve as potential examples and instances, makes for a rather more compelling conversation. As well as a rather fairer read of the concern voiced.
Are you super-rich and unaffected by this, or do you just enjoy being reamed by massive rent-seeking corporations?