Yes, a huge reason for training and dieting is aesthetics - looking better.
This will continue to be the case, but I believe the way people will reach these goals will change.
Training for performance will almost always lead to a much more aesthetically pleasing body. It also allows us for more measures of progress, will help avoid injury and live longer!
What happens much of the time is people train for simply appearance purposes and they lose motivation when they don’t see a slim body or a six pack straight away, this leads to temptation to think none of it is worth it and many people just give up.
If you set yourself performance goals it is much easier to monitor progress, if you are getting stronger or performing better then you know you’re body is changing for the better.
Whether training for a sport, or just for better gym/health/life performance, training for performance goals will build a great-looking body just as quick, if not quicker, than most bodybuilding-type training programmes.