Although it can be intimidating partner-based training is a staple of any martial art. Nobody enjoys being hit (outside of weird BDSM culture of course) but if you expect to improve, it cant be avoided. You won't get any better at fighting by striking a stationary object and pretending to defend yourself. As my coach says,"You haven't learned a thing until you've been hit."
Training with a partner helps you find your range when trying out different strikes. There is a big difference between training with a stationary dummy or heavy-bag, and training with a moving target. In a real fight, your opponent will not be standing still.
With practice, one can learn to find a good range for various strikes even while the target is on the move. Both people will develop proper footwork, strike connection, speed, upper-body movement and focus. Pictured below is a lead-knee attempt that was ineffective due to being too close to the target.
Another reason why I prefer partner-based training is the accountability and encouragement that comes along with it. While training alone, one is more likely to quit early or give up on that last set of pull-ups. For some reason it can seem okay to fail when you're alone, but being seen as a quitter in your partner's eyes can be twice as painful. This is a double-edged sword. Nothing fires me up more than some positive encouragement but, "Nice! Good contact!" and "Come on, Gavin! You can do more!" tend to have the same effect.
The social aspect of partner training is also fantastic. I have met some of the kindest and most insightful people through this type of training which has helped me to build confidence, social skills and mastery in what I love. So, next time you're looking to train, grab a buddy! The only thing better than leaving the dojo drenched in blood, sweat and tears is doing it with a pal.