Imagine doing everything you’ve ever done right handed but expecting the left to have the same size or skill level. Unless you are ambidextrous, you’ve been brushing your teeth, writing, swinging a bat or a club, kicking a ball one way your entire life. Maybe an athlete who practices their skills on both sides daily will have a little bit less disparity between right and left side.
But most people living a perfectly normal life are just not practicing skills or tasks with both sides. When you multiply this by 20, 30, 40, 50 years…you are going to have some imbalances. There is no direct link between muscle imbalance and injury. Yes, weak links on BOTH sides can fail and may need to be addressed. But left or right being bigger or stronger is not directly causing pain or injury.
I’ve been working out for the better part of 20 years. My left arm is still the limiting factor for a heavy dumbbell press. My left leg pistol squat is weaker than my right. I have a little more development visible on my right chest, arm, upper back. It’s perfectly normal and healthy.
Unless you are bodybuilding, for which it does matter, just work hard and incorporate some single leg / single arm activities in your programming. You don’t need to spend countless hours working on every little flaw or else you wouldn’t get any meaningful progress.
We are all flawed. The human body consists of 200+ bones and 700+ muscles. Do you really think they are all perfect? If we addressed every little imperfection we’d be moving backwards in our training. FOCUS ON WHAT MATTERS MOST, then do some fine tuning when things aren’t working the way you’d like them to.
Pursuing more symmetry (unless bodybuilding or you have a specific injury/reason to be working a weak link) is wasted time and effort that could be moving you forward. A good program incorporates some single arm or leg stuff and that should be more than enough for most of us.