Well, if you don't have an iPhone all the iCloud/Continuity/Handoff stuff is going to useless to you :)
But with regards to your other issues:
> The new Photos app doesn't honor mac system conventions.
This is being fixed. Photos eschewed Cocoa when it was first written and then realized this broke everything, so they're slowly adding these things back.
> The Mac App Store is repulsive to me in its philosophy, and its implementation has been inept.
I can't do anything about the philosophy, but there's a new App Store in macOS Mojave that's native as opposed to being webview-based.
> Airpods are cool, but connecting them with my MBP works only haphazardly as you'd expect of regular old Bluetooth headphones, not as you'd expect of Apple hardware talking to Apple hardware.
They're supposed to "just work", based on anecdota gathered from friends. Not sure why they don't for you.
But with regards to your other issues:
> The new Photos app doesn't honor mac system conventions.
This is being fixed. Photos eschewed Cocoa when it was first written and then realized this broke everything, so they're slowly adding these things back.
> The Mac App Store is repulsive to me in its philosophy, and its implementation has been inept.
I can't do anything about the philosophy, but there's a new App Store in macOS Mojave that's native as opposed to being webview-based.
> Airpods are cool, but connecting them with my MBP works only haphazardly as you'd expect of regular old Bluetooth headphones, not as you'd expect of Apple hardware talking to Apple hardware.
They're supposed to "just work", based on anecdota gathered from friends. Not sure why they don't for you.