Imagine a university student who has worked hard through several semesters of Russian. Then summer arrives, the required courses end, and there is no class on the timetable to keep the language in use. Skills like these can fade surprisingly quickly once they stop being used.
A small, ongoing group with a tutor could give a student like this a steady reason to keep speaking, through summer, winter break and time abroad. The point is not speed. It is never letting the language go quiet.
A student who keeps practising like this could reach graduation with the language still usable, and with options such as study or work that calls for Russian that might otherwise have slipped away.