Here is the problem: Collect a hundred, or a thousand, of those, and your life is miserable and your marriage doomed. Do not pretend you are happy wi… - Jordan Peterson

If you are not capable of cruelty, then you are absolutely a victim of anyone who is. For those who are exceedingly agreeable, there is a part of them crying out for the incorporation of the monster within them, which is what gives them strength of character and self-respect, because it is impossible to respect yourself until you grow teeth. And if you grow teeth, you realize that you're somewhat dangerous, or seriously dangerous. Then you might be more willing to demand that you treat yourself with respect and that other people do the same thing.
That doesn't mean that being cruel is better than not being cruel. What it means is that being able to be cruel, and then not being cruel, is better than not being able to be cruel, because in the first case you're nothing but weak and naïve, and in the second case you're dangerous but you have it under control. If you're competent at fighting, it actually decreases the probability that you're going to have to fight, because when someone pushes you you'll be able to respond with confidence, and with any luck a reasonable show of confidence, which is a show of dominance, will be enough to make the bully back off.

And you must be cautious, because making your life better means adopting a lot of responsibility, and that takes more effort and care than living stupidly in pain and remaining arrogant, deceitful and resentful.

Much of happiness is hope,