Why does PMI have the preferred project management certification?

I suppose I should first ask: does PMI have the preferred project management certification?

For context, I left the military not too long ago. As I was researching future career paths, the field of project management came up as something my skills could translate to. As I networked with people in industries, the PMP cert came up as a frequent recommendation. I know google has a project management certification as well.. I have not once heard that one recommended to me. Why is that? The only thing I have sometimes heard is that certain agile certifications are preferred over PMI-ACP.