Hi, I didn’t find existing issue or discussion so opening a new one here.
libinput has merged in support for 3-finger drag last year
in libinput 1.31 it also support 3-finger swipe at the same time even when 3-finger drag is enabled.
I think many people will appreciate having the option available in the settings. My wife was converted from Mac and this gesture was a deal breaker. There is an extension solution but it was quite janky.
For example how it works, you can check this reddit thread https://www.reddit.com/r/gnome/comments/1qs1pl8/i_patched_libinput_to_enable_threefinger_drag/