There is a way to lock formatting in Word for Windows on the desktop, although I'm not sure how well it plays with all the other variations of Word (Mac, Online, Android, old versions, etc.). It also may be too intrusive and get backlash from your team, so try experimenting with it before rolling it out to everyone.
Open the document (I'd recommend a template instead, but that also may not play well with others) in Word. Click either Review > Protect > Restrict Editing or Developer > Restrict Editing. That opens the pane shown on the left side of this screenshot:
Check the box under "Formatting restrictions" and click the Settings link to open the dialog box on the right side.
Check/uncheck the styles that you want to allow. If you want only relatively few, click the Recommended Minimum button, or click the None button and then check those few. You may want to check the two "Block" options at the bottom of the dialog, but definitely leave the "Allow AutoFormat" one unchecked.
Users will have to become accustomed to using character styles such as Emphasis (for italic) and Strong (for bold) instead of direct formatting. Other adjustments may be needed, depending on what kinds of formatting are required.
When everything is set up, click OK in this dialog and click "Yes, Start Enforcing Protection" in the Restrict Editing pane. If you want to, you can apply a password that will be required for turning off the restriction. (Don't forget the password. It's a good idea to keep a copy of the document for yourself that has no password.)