I'm logged into my Microsoft account on my PC. I paid for Microsoft Office or 365 years ago. I've been using Microsoft Office products since then. Now it's showing that I have to pay for them because it shows it is expired.
You are talking to your fellow users here. Not Microsoft.
You would have purchased Office, not Microsoft 365, which is a subscription product.
If you have Office 2016 or later your license is in your Microsoft Account. If before, it likely is in the form of installation media and a product key.
When you reinstalled Windows, that removed all programs from your computer. Whoever helped you with that should have alerted you to that sad situation.
When you sign into your Microsoft Account, go to the Subscriptions tab.
https://account.microsoft.com/account
At the bottom of that page, it will show you any purchased products that have been linked to your account. If something is listed there, you can download and reinstall. If there are no purchased products listed, you will need your original installation media and product key.
This is a user-to-user support network.
Microsoft is not hearing about your problems from what you post here. You are discussing a problem with your fellow users here. We can give good advice about how to work with Word as it is and give suggestions for making it work properly.
Designers and their supervisors do see feedback. (You will almost certainly not get a direct response to that feedback but they do see it.)
Here is more about that:
https://answers.microsoft.com/en-us/msoffice/forum/all/giving-feedback-on-microsoft-word-or-other/8df81a9b-84aa-46ef-bf88-24fb7fec96ba
I suggest using the public feedback portal so other users can see your feedback, comment and vote. If you want, you can post the URL of your feedback with your question here to lead others with the same problem to your feedback. Be the “squeaky wheel” that gets fixed!