A Chromebook is much closer to a desktop OS than a tablet OS. So you can see the file system, it assumes a keyboard and mouse are always present, etc. Where it runs into issues is the lack of apps, which Google are trying to fill with Android apps. I admittedly have not used one lately so I cannot comment on how good the Android apps are. If you are in the Google world, a Chromebook can definitely be more than sufficient as long as you don't need the traditional pro apps such as Adobe, or a productivity suite like Office (and no Google Docs, etc are not on the same level as Office).
So, yeah, Chromebook are rather good, much better than what they started out as. Having said that, my last Chromebook was an Asus that was a "2 in 1" and while it was perfectly acceptable as a laptop, it was garbage as a tablet. Classic case of a desktop UI with touch slapped on leading to a less than great experience. I would never use the touch on a regular basis on that particular iteration.
Which is one of my main arguments against mouse support on iOS. You can't just slap it on. It has to be thought out thoroughly and supported properly, otherwise it is a feature that won't get used while introducing complexity and confusion.
I can define it pretty easily for you.
A 2in1 Chromebook is mainly a light, secure laptop, that can turn into a tablet for casual use. It's mainly a laptop that can also be a tablet. It was not designed to be a tablet first and then a laptop. It's for people who prefer a laptop that can be a tablet.
An iPad is a tablet first, and now apple is trying to convince people it can replace a laptop. The iPad is a touch only device (for now). The Chromebook is a point first AND touch device.
Google has worked a lot on the interface of the OS in the last year and it is totally touch friendly today.
Also, when comparing one to another, please don't go ahead and compare a $299 Chromebook with a $1000 tablet. Get the best Chromebook money can buy and compare it with the best tablet money can buy (the iPad). From my experience with both devices I prefer the Chromebook approach more because it fits MY needs. I need more of a light laptop that I can turn into a tablet now and then. Android apps runs mostly great (especially those who target Nougat API's). They work great with touch and a mouse and keyboard. But like everything Google, it's not as polished and some things can be rough around the edges.
Having a full blown browser + mobile apps on one device is a great combination and it works very well with keyboard + mouse + touch + stylus.
It's a laptop + tablet that you can also plug in and power two monitors while at a desk. I'd love to see Apple implement this on the iPad.
As I stated before, I also have both new iPad Pro's (and an iPhone and a MacBook) and they are fantastic tablets and devices. Google will never reach the level of polish Apple has with its products but as soon as I actually tried to use the iPad pro for actual productivity and get regularl office work done, this polish feeling vanished very quickly because I had to reach out and touch the screen for every little thing.
Just think about , every mouse click, every single one - requires you to touch the screen.
We click our mouse about 100+ times per hour, if not a lot more. Having to reach out to touch the screen 100+ each hour, on a 12.9'' display...i'm sorry but the arm pain this has caused is significant. The iPad can never be a true, comfortable device that people can work for long periods as long as it won't have a proper pointing device. These devices were invented for a reason, which is mostly ergonomic to the human body. There is no need to try and re-invent the wheel here. I'm sure Apple will figure it out, probably in the form of a trackpad that can mimic all the gestures we do on the iPad screen.
Touch is great for devices we hold in our hands. When you take such a device and dock it to a keyboard with the intention of working with it on a desk, it must be combined with a mouse/keyboard for comfortable use.