If you're working in a corporate environment, this may not be viable. LibreOffice is great software, but it's not 100% compatible. Things may look slightly different, get lost or otherwise cause problems. I've really tried, but at the end of the day I occasionally do need to use actual Microsoft Office.

Yep. And then there is Visio which gets used a lot where I work. LibreOffice Draw doesn't come anywhere near it. It saves a lot of grief just to give our Linux users a Windows VM with Office on it if they need to do any significant docs or drawings.

I used Word to write a reasonably complicated document that necessarily used tables. It was one of the most frustrating, bug inducing experiences of my life. I had to open the document and edit it in LibreOffice to get any sort of stability.

How do I join a live editing session of an Excel file with several people using regular Excel with LibreOffice?

I can't.

Or the same with PowerPoint.

I can't.

In a modern workspace it's not just local software running solely on just your local machine emailing around files or clobbering changes in some corporate file share.