Photographers own the copyright on their photographs.
Period.
No, photographers don’t always own their photographs. It depends on the agreement between them and who they shoot for.
Period, unless the photograph is a “work for hire.”
Period, unless they have sold their rights to the photograph (ie, did not retain any).
Etc.
Not necessarily accurate. You can sign agreement with a freelancer that all photos that you pay for belong to you and only you. You own the "negatives" (today pixels) and all rights to them.
I learned this the hard way back in the 70s when someone in my company hired a freelancer to take a photo specified for a specific brochure. It was a great photo and afterward ended up being used in a number of applications. The photographer came back and sued for copyright violation and it was a mess. We ended up paying him off (and he screwed himself totally BTW because we never used him again) and revised the services contract so that anything a freelance photographed under contract to us was our property, and he had zero rights to it. The contract required the photographer deliver the negatives to us.
Much different in the digital world today, but just because someone takes a photo does not mean they own it. Read the contract.