And if I may expand upon this, I bet you don’t think this is MacOS being objectively terrible. There are lots of Mac users and they seem to get along with it just fine, and in fact they look at you weird for fussing about it.
I’ve often pointed at an LTT video where they had iJustine on as a guest, and Linus and Justine swapped platforms, him on a Mac and her on a Windows PC, and they were given a series of tasks such as “install Slack. Take a screenshot. Save that screenshot as a PDF. Save that PDF to a thumb drive. Attach it to a Slack message” etc. And both of them hit points where they said “Oh, you’re going to struggle with that.” Apparently the keyboard shortcut to take a screenshot on a Mac makes no intuitive sense, and at least at the time Windows 10 didn’t ship with software capable of saving a word processing document as a PDF. They both struggled, and they both hit things where they thought someone unfamiliar with the platform would struggle.
Just as you will encounter culture shocks transitioning from Windows to MacOS, you will encounter culture shocks transitioning from Windows to Linux. The time to get used to a new OS isn’t when a client needs some important documents right away.
Do not get me wrong, OP. I would love to see your independent law firm running open source software rather than relying on the megacorporate duopoloy. I think you can do it, but I want to be clear that you will likely need retraining and experience in the new platform.
I do strongly encourage trying a distro or three out in VirtualBox, right there on your Windows machine. Give it a look, play around, follow some tutorials, have some fun. Install VLC and LibreOffice on your Windows machine and see if they’ll do the work you need them to. I also strongly encourage you to come tell us how it goes.