Cmd+G - G for Go, and I agree that having to go to the menu bar item called "Go" is not super discoverable, but I found it once, and been using Cmd+G since then. I guess users that don't use shortcuts have more problems with these.
> Copy+Paste is not?
Cmd+C Cmd+V ? I am not sure this really needs an icon. I mean, if you go to the "Edit" menu, you see the shortcuts for Copy, Paste, and Cut, which are the same as on Windows or Linux, but using Cmd instead of Ctrl (which is consistent with the rest of the OS).
> tabs were finally added very recently
Tabs were added a long while ago, 5 years at least. But you don't even need tabs for this. I just do Cmd+Shift+Left to tile one finder window to the left of the screen, and Cmd+Shift+Right to tile another window to the right, and that's it: two windows, side by side.
I mean, it's not i3 or sway, but works fine.