Is it better to play multiple sports or focus on ONLY table tennis?
This is up to each family.  Many top table tennis players like Kanak Jha started out playing soccer or other sports.  Around age 11-12 years old, many of them decided to dedicate more time to table tennis.  Professional players usually practice around 25-30 hours/week.
 
 
What about ________   ________  US table tennis superstar who many years ago got burned out from only playing table tennis?