Switch is 4 Arm A57 at 1ghz which is about 17,000 mips however the Switch uses 1 core purely for the operating system which brings it just below 13,000 mips for games. The wii u for example has 9,000 mips but has a dedicated arm chip to runs its operating system so remains at 9,000 mips for games. This puts the Switch well below Xbox 360 and PS3 let alone comparisons with Xbox  one or ps4. While mips only gives a general guide to performance it is actually known to inflate the performance figures of ARM chips because they are RISC and have a smaller instruction set than some other chips like x86. Generally a x86 processor mips rating would be a more powerful chip than an ARM at the same figure but this all depends on application. The Switch basically sits between wii u and Xbox 360 in cpu performance. There is no doubt though that the technology is superior in Switch. It achieves performance just below Xbox  360 with 4x 1ghz Arm A57s but the Xbox 360 has 6 threads at 3.2ghz on its powerpc cpu. So if you did a unorthadox sum of mhz. The Switch almost achieves 360 performance at 4ghz what takes the 360 close to 20ghz (6x3.2ghz) to achieve. If Nintendo had kept the Arm A57's at the same speed as the Nvidia Shield box 2ghz then the Switch would have shot past the 360 in performance but sadly they didn't. This would have bought it up to about 2/3rds the cpu speed of ps4/xbox one cpu's making it easier to run more sophisticated game engines even if the output graphics were weaker in comparison. 

https://en.wikipedia.org/wiki/List_of_ARM_microarchitectures

It goes without saying that its not a linear demand and the developers may have to make adjustments but as a general guide its very true even if the difference in versions requires a few nips and tucks to get the game running well depending on weaker or stronger parts of the specification.  I don't own a pro or intend to buy an X in the short term myself. I thought I would buy a ps4 pro because of VR but that also hasn't got the software range that justifies the purchase for me. Still very happy with my standard ps4 and xbox one for the moment. I'm trying to dial back on my gaming platforms as have a huge backlog of games to start.

No. Bottleneck and/or bad optimization on either CPU or GPU prevents 60 fps.

For example, numerous titles use dynamic resolution to maintain 60 fps. That's primarily a GPU issue.

I didn't forget it just doesn't fit my point.  Which is that Bungie is not going to let one group of players in a game's multiplayer lobby (PS4+PS4Pro or XB1+XB1S+XB1X) have a framerate advantage.  PC its fair game because they are their own closed multiplayer ecosystem.

That makes no sense to me.

How is PC with rigs that do 30-60-120-144-165-180-200-240fps any different than an Xbox One at 30fps and the Xbox One X at 60fps?

Because on PC it is universally accepted to have unlocked framerates while on consoles it is universally accepted to have locked in framerates.  PC players accept the fact that if they want to compete in multiplayer settings they need to be at least 60FPS +.  Try telling a console player that the guy across the screen from him playing with the same controller on a machine he bought from the same company is getting double the frame performance.  Won't end well.

That's really dependent on the game.
If you are playing a competitive/twitch shooter along the lines of Overwatch then framerates are indeed king, even then some gamers are happy with sub-60fps and still do well.
If you are playing a game like Minecraft then it doesn't matter if one person is 10 fps and another is 1000fps.

30+60fps can work fine, It has been fine on PC for decades, so it's more than possible on other platforms in my opinion.

Besides. The Xbox One S is actually more powerful than the base Xbox One. They don't always get identical framerates either.
The Xbox One X should take a game like Battlefield 1 and run it at a full 60fps, where on the Xbox One it will be 30-50fps.

And since my comment was specifically about a shooter, you can see why I say Bungie wouldn't do it.  And yes, some gamers would be happy with sub FPS and do ok.  Now, make that - based on just the PS4 Pro data we have of roughly 1 in 5 PS4s sold are Pros - 80% of the userbase playing at that lower framerate in the competitive multiplayer game.  

Start to see where it becomes an issue for an environment that has ALWAYS had equal framerates for each user in it?

Playstation is a different ecosystem to Xbox though.
The performance delta between the Xbox One and Xbox One X is much larger than the Playstation 4 and Playstation 4 Pro.

But I digress. Battlefield 1 will be 60fps on the Xbox One X. Sub-60fps on the Xbox One and will co-exist fine.

Did they announce that?  I missed it.  If that is indeed the case though, and they have them playing from the same multiplayer lobbies, I find it to be a huge mistake on the part of the devs and a disservice to the majority of the console userbase for Xbox.

Edit: Also, the PS4 part was to give a baseline of what we might expect for adoption rate on the XB1X.  Pro is roughly 20% of what is sold right now according to Sony, so I used that as the baseline for my percentage there.  The fact that the XB1 to XB1X disparity is larger actually makes the issue I am saying will exist by changing up framerates on competitive games the two systems play together worse.