Most people will never imagine learning a piano without the guidance of a teacher. They believe that there is not much of a chance to master it without professional instruction. But despite the piano being a difficult instrument to pick up, it is not mandatory to be taught by a professional.
The piano can be learned through self instruction. Even teachers do not have every student becoming pianists, so proficiency is not a sure result from employing one. Many piano teachers are no more than guides who enforce practice, which can be done by anyone with the right discipline.
Piano teachers could also have the reverse effect on someone who is keen to pick up the instrument. A strict or disagreeable teacher could sour the whole experience for a student. If the piano lessons are boring, students might lose interest and end up turning their backs on them.
If there is a strict budget involved, then a piano teacher will be out of the question. Most teachers charge monthly fees that average hundreds of dollars, depending on their qualifications. They might provide some experience in guidance, but there are just as many willing teachers online who provide their opinions for free.
With more leeway in the learning process, it can result in greater artistic expression. That is a freedom that might not be afforded to students in a piano school and under strict teachers. It does not encourage deeper exploration and understanding of the music as they could be influenced to play and think in a certain fixed way.
By becoming self taught, there is a more relaxed atmosphere and feel to learning how to play the piano. To prevent the process from having less than desired effects, discipline should be a factor while learning the instrument. But it is a method that can fit the most trying of learning ability, and easily customized for all.
There should also be considerable usage of online piano lessons that are freely available. They will add to the whole experience, and can be suitable substitutes for piano teachers. The personal touch is lacking, and sometimes it might still take some human explanation to understand certain points. But these can be replaced by getting involved with communities who have a passion for the instrument.
There is no clear advantage to having a piano teacher compared to teaching yourself how to play. In fact, it could be easier to learn the piano yourself, and indulge in endless hours of fun with music that you enjoy. The millions of self taught professional musicians worldwide will not disagree at all.