My first serious telescope was a Jaegers 80 mm f/15 refractor and I had no problem seeing the GRS, Ganymede crossing the globe or shadow transits on Jupiter or the Cassini division in Saturn's rings or its major belt or even Uranus and Neptune as perfect blue-green discs or the polar caps and Syrtis Major on Mars, in many cases the first time I observed them
It does take some time and practice to get accustomed to viewing through an astronomical telescope at astronomical objects, but it does not take years, at least not in my case. After several observing sessions I was well acquainted with what to expect from my telescope and I was sure I was seeing everything it could present to me, simply because I read a lot about observing and compared my experience at the eyepiece with what the experts were saying.
And I knew that if I had a larger aperture telescope I could see more. At the same time, I came to realize that what my telescope revealed was dependent upon the seeing. Point in fact, to me a 10" f/5 Newtonian shows more planetary and lunar detail than any 4" aperture, regardless of its ilk, as long as the seeing is reasonably good, and I'm talking 5-6/10.
Maybe other's experiences are different, but that is mine.