I’d trust some random people running an activity pub server just as much as I’d trust Meta with my personal photos: I won’t.

I'm pretty sure Pixelfed wasn't intended to be a place to share your personal photos - it's meant for sharing photos you want to share with the public - could be a circle of friends or the whole world. Photos like pictures of your cats, food, landscapes etc. It's a place to share photos with friends, or a place to connect photographers with other photographers.