Of course it is, it's worth it for many people and firms. The problem with threads like this is that many believe since they are successful in using a piece of software that everyone else should be as well. Those who pay for MS Office do so because they need so, nothing more. A mobile app of anything is a far cry from a full desktop version, I've even had people try to convince me that I could use my iPad Pro as a full CAD system, sure, maybe if I was designing a bathroom for my daughters Barby house, however I'm not going to go into a clients office and show him blueprints for a new 50,000 sqft. Building designed from an iPad Pro. Could you imagine trying to work with a team of about 7 guys on the same project using iPad Pro's. I mean forget the fact that we all work off of dual 32" 4K monitors now, connected to dual XEON CPU workstations with dual Nvidia Quadro cards, just dealing with files in iOS would be enough for my staff to go bat sh*&t crazy and probably hang themselves. These guys just can't get it through their heads that even though there are a few apps that can display CAD projects and even do light editing, no professional in there right mind would ever use such a device for this type of work except for maybe demoing what a finished project might look like by utilizing files made from a real computer. Pixar for instance might use an iPad Pro for a meeting, this is what a character would look like, that character however was just copied onto the iPad Pro, not designed and created on it, the difference from content consumption and creation.
This whole notion of the iPad Pro being utilized as a laptop replacement device is ubsurd to me, at least in the professional sense. As a consumer device, sure, I guess, the same people that are comfortable with using a ChromeBook for their home office could probably use an iPad Pro as an alternative. Though I personally would probably prefer the ChromeBook as not only are cloud apps more powerful than most mobile apps, albeit non-graphic related mobile apps, though cloud apps even in this department of vastly becoming pretty great, i.e. I'm running Photoshop on my Pixel ChromeBook, yep, the same Photoshope, soon Adobe will be releasing their entire CC to the cloud. ANyway, you have access to a mouse, a better file management system, better multitasking, etc. all things that are is still important to a lot of people for productivity work. I mean just using my iPad Prp for 10 minutes with the keyboard without a mouse was enough for me to call it quits, having to constantly reach up and across the keyboard to navigate the UI get's old real quick.
My whole point is, the iPad Pro, even with the Pro, is still a consumer device, running a consumer OS, utilizing consumer based apps. Saying that the mobile version of Office is a viable solution for every task is simply absurd. Like the CAD programs, mobile Office was designed to review content firstly and foremost, with light creation capabilities second, yes light, anyone who is thinking about creating a 100 page workbook using an iPad Pro with a very limited mobile version of Office is simply stupid, wrong tool for the job. The second you start needing something even as simple as a mass emailer, mobile Office becomes as useful as cruiz-control on a Lamborghini.