Sometimes it's the only option you have. Sometimes walking away is the healthiest thing you can do. Sometimes saying "I've had enough" is the most generous thing you can do for yourself and those involved. Of course, whoever is on the receiving end of this conversation may tell you that your "giving up", but the question I have is what are you giving up by subjecting yourself to whatever it is longer?
I know I've been in situations where if I stuck around that would mean my mental health would suffer. I don't just mean romantic relationships, but it may be a job, a friendship, or even a phone plan. We shouldn't damn someone who has had enough. You will always have those people that when the going gets tough they get going, but for the most part not everyone is out to end relationships and close all those around them out. Most people want and need that human interaction, but we have to be mindful of what we are willing to stick around for and work through. We have to make tough calls on situations that may be worth walking away from. Not every relationship is salvageable. Hell, look at the guy who went from Sprint "Can you hear me now? Good", to the Verizon Red Check Mark. Not all relationships are made to stand the test of time. And it is your responsibility to keep yourself in mind.
Walking away from a toxic situation, environment, or person doesn't mean that you are "giving up" or that you are "childish" or "overreacting". It simply means that the pros no longer out-weigh the cons. The definition of insanity is literally doing the same thing over & over but expecting a different outcome. If we continue to subject ourselves to the same toxicity over & over, we will have the same outcome time and time again. Listen to what your inner monologue is telling you- you'll know when it't time to take a step back... even if you don't realize it.
Walking away doesn't always mean forever either. If you have been around for a while, you know I am a firm believer in seasons. Some people are only around for one or two, and some last through years of seasons with you. But there are a few who may come and go as seasons and you change. You will need certain people in your life for whatever growth stage you are at, and others aren't as prominent- but they may be on the next go around.
Remain humble however if you are the one who is being walked away from. You may not be a "bad person", but you may not be what someone else needs.
All I am saying, is know your limits and respect them. You don't have to stay in a friendship that is no longer bringing you joy or may have turned one sided. You are allowed to end a marriage if you are too different of people now. Sometimes, that happens; we are humans and we grow- we were never meant to stay the same. You are allowed to go and change & so is everyone you come into contact with.