Most of the time concertos are completely useless because it's so hard to find an orchestra to play it with you
You can just learn concertos as solo works. Some of them (prokofiev no. 2 chopin) are so rad they're worth the effort, even if you'll never play with an orchestra.
It really depends on your goals. Learning both soloist works and concerti come with unique challenges that help you grow as a musician in different ways.Focusing on solo works you improve musicianship by really delving deep into the the piece and making it your own. You are more free to interpret the piece. You can choose your own rubato, voice chords the way you want, focus on articulation and dynamics a lot more. You can do all that without having to think of how the orchestra fits in. Plus, the big pro of easier opportunities to perform those works.On the other hand, working on a concerto will force you to collaborate with others, a very valuable skill in the music world if you can do it well. Another big pro is that you need to think in a new way about how the piano fits in. You develop better listening skills in music.
Thanks! I do enjoy playing with other people. I asked this question because I'm trying to decide between devoting the next three months of my life preparing for a concerto competition (playing Beethoven's 3rd), or else focusing on my other solo-rep goals (Chopin Ballades, Beethoven Appassionata, Liszt Dante Sonata ... not necessarily all at once, but you get my drift). The thing is, the concerto competition won't always be around ... and this year is my last chance to compete in the student category, where I might actually have a chance at winning. The solo pieces, on the other hand, are very attractive to me ... and I've already done a substantial amount of work on each set, so finishing all of them over the next six months or so is a plausible goal for me.But the concerto competition ... I really want to try it. I already missed two last year, and have felt crappy about it ever since.