When you are playing someone your own level, or higher, you want to play the percentages and minimize unforced errors.
You want to hit deep and over the center of the net if possible. Hitting the ball back along the trajectory from which it came is safe and easy.
If your opponent hits down the line, respond with a hard cross-court drive and move to the center to cover possible returns
When you get a short ball, see lots of open court, catch your opponent leaning/moving away-- then go for a placement/winner and follow the shot to the net.
Or-- chip to backhand, mid-court, follow ball to net.
Or-- if the opponent is way deep, drop-shot and come to net.
These are some of the times changing the direction would be a positive rather than a negative.
Since changing the direction of the ball requires more effort/timing/risk, do so only when you can see that a clear advantage to be gained.