Did you know you can add 5,000 items to a shared album on your Mac or iPhone? That’s a lot.
Personally, I don’t need or want to access my entire photo collection on my phone (I’m not using iCloud Photo Library but download my phone photos manually to my Mac). Instead, I like to use shared album for photos I want to see on my phone. Maybe from a holiday or often it’s business related. I add the photos to a shared album and then delete them off the phone.