It is, because there may be multiple things synchronizing their inputs and outputs to the refresh, which causes the refresh-related latency to be a number of frames. E.g. in some Linux compositors inputs are latched with the refresh, apps themselves may render in sync, and the compositor also draws in sync; the GPU driver would also introduce at least a frame of latency typically.

Another factor is that some (many?) 60 Hz displays buffer a whole frame themselves, and often don't have quick response times. If you go from a 10 ms response time IPS screen with a frame buffer to a 120 Hz gaming screen with 2-3 ms response time, you already got a difference of about 25 ms just in the screen itself.

8 ms is hard to notice. 50 ms less so.

The difference is pretty huge, even on systems that are much better tuned than Linux desktops (e.g. Windows 10).

That being said, while it is very nice and feels nice, it's not necessary for development work; I spend most of my days developing on a system over a VNC connection through a VPN, so the basic input lag of that setup is around 200-300 ms. Gnarly yes, but not particularly bad for text input. You get used to just do everything very slowly with the mouse.