I only very recently changed my System Settings > Desktop & Dock > Windows > Prefer tabs when opening documents to "Always". I'm pretty sure the default is "In Full Screen".
Now, something like TextEdit creates new files in new tabs rather than new windows. It's great! But by default, everything on macOS seems to use windows rather than tabs. I don't even think most people know about the "Prefer tabs" option at all.
I only very recently changed my System Settings > Desktop & Dock > Windows > Prefer tabs when opening documents to "Always". I'm pretty sure the default is "In Full Screen".
Now, something like TextEdit creates new files in new tabs rather than new windows. It's great! But by default, everything on macOS seems to use windows rather than tabs. I don't even think most people know about the "Prefer tabs" option at all.