Firstly what you are asking is highly subjective. The amount of progress vary widely from person to person due to a lot of external factors such as frequency of piano lessons, duration and effectiveness of practice, performing experience, etc. But anyway, there are many many factors that make up a good all-rounded pianists. Please do not make the mistake of judging your progress from the difficulty of the pieces you are playing, but rather from how well you play them. And also learning piano is much more than just keyboard skill, there are many other things such as music theory and appreciation, musicology ( music history ), scales, sight reading, aural, accompaniment skills, concert experience, etc. In my opinion, a pianist should be proficient in all these skills, a pianist that only know how to play the piano is missing out on a lot of developments and to some extent can be considered as a dabbler.
A few suggestions to check your progress:
- Ask your teacher to measure whether your progress is acceptable taking into account the efforts you have put in.
- Go to other student recitals or join amateur competitions and check out people with similar learning backgrounds as you.
- Take graded music exams. Yeah, I know you have to do a lot of things like scales and aural. But to be a proficient pianist, there's no excuse not to do the, in fact, you should love doing them.
I wish you could drop this question. This question will just spark another endless debate.