Because Apple's focus is to lock people in. They do a superb job at it. I’ve been in a slow but deliberate move out of the eco-system. Work to Office completed. Apple Music to Spotify completed. Apple's broken Mail app is a bust so far as I'm not going subscription for a Mail app and the free one's are crapp. The Apple TV was replaced with a Roku costing a fraction of the price and is far more stable, no matter how pedestrian it looks. The Roku is also free from Apple's never ending quarrels with the Xfinity's of the world and gets functioning apps while Apple gets nothing (by choice) or crippled apps. Currently finding Adobe's Photography package has me covered for photography on MacOS, iOS and sharing far better than Apple. $10 a month I gladly pay.Thanks, I look at both.
But I have to ask... why doesn't APPLE make it easy/simple to plug in an external drive and be able to read ANY Photos Library???