Chubb or any other insurer that has a fine arts/antiques division. Jobs in appraisal, claims, business development, marketing, client relationships.
Any of the auction houses (they are very prestige conscious though- where you get the degree matters).
Museums have tons of business functions- human resources, finance, marketing, development and fundraising, educational programming and outreach.
The companies that sell to museums and auction houses- there have been some fascinating stories recently about the use of digital imaging in restoration, specialty chemicals that have been developed for cleaning without destroying the original work, transportation companies that can move a valuable violin or sculpture or an entire installation.
The FBI has some of the world’s leading experts on provenance, money laundering, forgery. Ditto Interpol.
There is no such thing as a useless degree, but there are plenty of people who find their degrees “useless” because they don’t take the time to research and network.