The modern orchestra has its beginnings in the courts of the Renaissance when groups of instruments were used as accompaniment for vocalists and dancers.
Then, the instrumental ensembles were seen as party entertainment; now, they are entertainment in and of themselves. This change began in the late 17th and early 18th centuries when orchestras began performing by themselves because composers began to write specifically for instrumental groups.
Composers began adding more layers to their music by creating more harmonies and adding more wind instruments. By the time of Beethoven, in the early 1800s, the orchestra’s wind section had two flutes, two oboes, two clarinets, two bassoons, two trumpets, two horns and timpani. The harpsichord, which had previously been a member of the orchestra, was being phased out, while the trombones and more horns were being added.
The orchestra today has larger percussion and brass sections. Both sections would tell you that it’s a good thing.