Another explanation is that these traditional media outlets were/are having a hard time economically, making it

a) easier/cheaper to buy them, and

b) more attractive for someone considering themselves a philantropist, given that they are by many considered to provide a vital service to society.

You're free to disagree, especially with that last bit of course. But assuming this view, "philantropists" buying news outlets is at least internally consistent without assuming malice.

Of course, whether or not someone like Bezos should be considered philantropic in his motivations is another matter entirely...