There are many advantages of playing the piano:
- your fingers don't get sore or bleed, like when you play other string instruments
- it is not disgusting, with condensated breath dripping out of it after a while

- you don't have to pose your body in an uncomfortable or ridiculous position. (Come on, playing the violin isn't exactly ergonomic, and there is a reason why "air cello" is not as popular as "air guitar", just try it yourself, hahaha.)
- the piano can make a rich sound by itself without demanding addition of other instruments
- you don't have to study a difficult technique just to get a sound from it. You just press down the keys, everyone can do it
- it is an extremely versatile instrument with a huuuge frequency span
- what instrument can possibly look more beautiful and impressing than a grand piano in good condition?
Well ... there are some disadvantages too ...

- moving this instrument around is not easy ... most of the time you have to rely on the instrument that is available at the venue, you cannot bring your own trusted "companion" with you unless you are Liberace or Elton John
- you cannot move around while you are playing. OK, so there are a few other instrument with the same disadvantage, but let's say that this is a non-parade instrument ...
- it requires a lot of space
- the instrument is incredibly expensive compared to many others and the acoustic versions - which are the best - require periodic tuning and maintenance by an expert
- playing the piano is very difficult ... Yes. Making it sound is easy, as I wrote here above, and you don't need instructions to pick out a melody on it by ear. BUT it still does not mean that is it easy to master the piano. You have ten fingers and also three pedals (or at least one) and the music often consists of several voices. Only church organs are more complicated in this aspect, but let's count them as pianos as well, then. Playing the piano simply requires a lot of brain work!