If you have Microsoft software on your computer, then it's not your computer, it's Microsoft's computer.
Their business model is to eliminate ownership by their customers, and replace it with rental - after you have bought their shit, they expect you to keep on paying for it, forever.
They don't want you to use Office locally; It's easier for them to extract cash from your wallet if they force you to use "the cloud". Office365 and OneDrive are just like working locally (only slower, more expensive, and less reliable), but they have one massive advantage: They give complete control over everything to MS, so that you are their prisoner forever. Oh, sorry, did I say 'advantage'? I meant 'trap'.
They have been working up to this point slowly, so that the frogs are never prompted to jump out of the pot; And they will tell you that handing over control to them is essential for your security and safety. It's totalitarianism, 1930s style, but with a modern technological twist.
They get away with this, because most businesses and many private individuals genuinely believe that they have no other option than to use Microsoft products, if they want to do business with other MS customers victims.
This is not, in fact, true in most cases. Most home users need to be able to produce documents in MS Word format, so that their correspondents on the other side of the Redmond Curtain can access those documents; However this is as simple as selecting "Save As...>Microsoft Office (.docx)" in Libre Office.
Libre Office is available for Windows; But if you really want to own a computer (rather than pay through the nose to borrow one from MS), I heartily recommend Linux Mint, which is free of charge, and has a user experience rather similar to what Windows was like before MS went full-blown off the rails evil.
You can even install it alongside your existing Windows system on the same machine, and choose which one to run when you start up your computer. That way, if there is some particular 'Windows only' game or corporate software you need to use, you have the option to boot into Windows to do that.
In my experience, almost everything I want to do can be done either by Libre Office, or in a browser - and browsers don't care which OS they are sitting on. Firefox on Linux is basically indestinguisable from Firefox on Windows.
And there is a massive library of free software available for anything you do need (for example, while GIMP is not the same as Photoshop, it has pretty much the same functionalities; If you use Photoshop, your learning time to switch to GIMP is fairly short - comparable to re-learning any software package after a major upgrade).
Switching from MS Office to Libre Office has a negative learning curve if you were familiar with Office prior to Office 2003. It's like:
