Change sort order in Photos Library

In the all photos view, you can't do that.

I wanted to when I first started using Photos, but since have just got used to it the way it is. It actually makes no difference to the way you use the app.

Alternatively you can create a smart album with a condition that selects all photos, such as the one below, then sort that as you like, and use it as your main view.

If you are at the bottom when you close photos, it should open in the same position next time.

You can also use the "home" and "end" keys to jump to the top or bottom.

Or make the scroll bars visible in Photos. Then you can simply click the spot in the vertical scrollbar to jump to the position you want.

The Scrollbar settings can be changed in the System Preferences > General panel.

I find that it is "sticky", Photos remembers that I was looking at the bottom of the "all Photos" in the library, and opens up there when I start Photos.