Of course with AI one could go as far as adding a "Report this site doesn't work in Firefox" button that magically sends a report (+ suggested fix) to the people operating the website/app.
replyNot sure if you're aware, but this button does actually exist in the help menu, at least for getting a public report filed. I looked through our tracker and didn't find any report similar to yours though (..and Office365 has a ton of webcompat bugs on file...), so I'd recommend you and "others" to actually file those bugs.
Finding and fixing those bugs in websites (unless they're behind a login that you can't easily sign up for) typically isn't the issue, but getting ahold of the site owner sometimes is.
If we can't get ahold of the website operator, or they're slow or unwilling to fix it, we can ship compatibility shims in the browser.
Take a look at about:compat to get some idea.