What do you mean by open and closed? ChromeOS is based on ChromiumOS, which is open source. I guess macOS is based on Darwin technically, but the ratio of open source to proprietary is much higher for ChromeOS than macOS, no?

You can even install linux on Chromebooks, and ChromeOS has upstreamed / opensource many of their codes.

In other perspective, ChromeOS supports running Linux apps w/ GUI without much differences. You just open your terminal, type `apt install XXX`, then `XXX` should work out-of-the box.

I don't see any reasons that ChromeOS is less open then macOS

ChromeOS will run on any standard machine and subsystems (qndroid, linux) work decently good.

What concrete points makes you put macos as more open ?

For small businesses using Google Workspace, Chrome book is so easy to manage.

Ha, same. I absolutely love everything about my MacBook Pro.

> but it's definitely more open than ChromeOS.

I don't think that's entirely true. For instance, ChromeOS supports Mesa, which macOS has spent the past decade pretending doesn't exist.

I can't think of any sense in which this statement could be supported by facts.

ChromeOS is the absolute last desktop operating system I would choose to use for myself. Linux, macOS, and Windows would have to be completely dead and buried before I would switch, and at that point I might just consider abandoning tech altogether and joining an Amish commune or something.