Everyone has different use cases. You apparently didn't use the Surface Pro to its full extent, or it wouldn't be so easy to go back. There no equivalent project to either the Surface Pro or Note 8 in Appleland.
Trust me, I used the Surface Pro "to its full extent". Sadly, the "full extent" of that device is hampered by an atrocious operating system that doesn't work properly with a device manufactured by the same company. Microsoft has had five iterations and the same number of years to get this right, yet still it is riddled with issues. Blue screens of death, "hot bag" syndrome, "FlickerGate" screen issues, a complete inability to properly sleep, battery drain issues… The list goes on and on and on.
Seriously, I love the hardware.
Love it. The design is beautiful, practical and versatile. I adore the kickstand and Alcantara type cover. It makes the Smart Keyboard look like the floppy, overpriced piece of junk it is. All that is worthless, however, when
it simply does not work properly.
Every time I switched it on I would wonder whether it would wake up. Half the time the pen buttons wouldn't do anything. The other half of the time the pen itself wouldn't work either. And don't get me started on scaling issues… 1080p monitor? Get ready for giant icons/toolbars and being forced to logout with all your currently running apps open because Windows
still in 2018 cannot scale the UI properly.
Don't get me started on the quality control issues. I had six different Surface Pro's, all riddled with issues or faults. One of them had white blotches on the screen the second it was turned on, another a vertical row of dead pixels and on a third, the glass was physically detached from the screen out of the box. The return rates on these things must be horrific.
I've never owned a device so fantastic and maddeningly frustrating at the same time. Microsoft push firmware updates to the damn thing as if they are no more than security patches. Yet, even as late as last week, I would get a blue screen of death while the machine was effectively idle, not under load, and with a different error code from the previous ones. Again, I love the concept but the execution is a disaster.
And not everyone wants their phone messages popping up on their computer screen. If I did, both Samsung's SideSync and Cortana provide sycing, albeit not quite as good as iMessage. But like I said, I don't want that on my computer.
Fair enough. But for those of us who do want those things, the likes of SideSync aren't a solution as, again, it doesn't work most of the time. Aside from the fact Samsung is deprecating it (and its replacement apparently doesn't work either, judging from reviews), PushBullet is probably a better solution. Haven't used Cortana, so can't judge it either way.
You mentioned the AW is killer. I had one for 2 years and liked it but I'd hardly call it killer. In fact, I was shocked that I love the Gear S3. All the things you mentioned I find to be a better experience on the Gear S3 than the AW, largely because of the navigation and rotating bezel. And in the US, Samsung Pay is taken at way more places because of MST... we still have a lot of older terminals.
So a lot of this depends on personal needs and preferences.
It's not just personal needs and preferences, it's also circumstance and geography. Here in the UK, Samsung Pay supports virtually no major bank so it's a dead end. The only options here are Apple Pay and Google Pay, which also rules out the Gear S3 as it runs Tizen, not Android (so no Google Pay). It's also a dead platform - Samsung is rumoured to be ditching it for their next round of smartwatches. Like the Surface, it's really nice hardware hobbled by the platform it's on – if I am going to replace an Apple Watch, there have to be no compromises.
The Android Wear alternatives are all compromised at present – they are either lacking certain functionality, running old hardware or both and the platform itself seems to lack any clear direction.