'Is Economic growth purely beneficial?'

Yes (beneficial):

-Increase in GDP, increase in disposable income, increase in standard of living, increase in consumption, increase in AD --> multiplier effect

Depends on who experiences the economic growth, if it results in greater disparity between social classes it may lead to unrest

-Producing more goods and services, relying on importing less, so less volatile to exogenous shocks, greater price stability 

No (not always beneficial):

-Greater production of goods and services increase carbon emissions which is a negative externality on a third party

-It also depends on how much spare capacity remains in the economy (is then shown with a diagram)