Is it really worth it to get revenge on a lying and cheating ex who was also a manipulative and bad person? The short answer is yes, yes it is.
Relationships are complicated. People are complex, and they have layers of personality we can only discover over time. Oftentimes, people have different opinions and ways to see the world, and if the couple's communication skills are not very good, that can lead to misunderstandings, fights, and even dramatic breakups.
Now, my boyfriend is a doll, but I've seen my fair share of toxic couples whose issues were way beyond not seeing eye to eye on a day-to-day matter, or a difference of opinion. Most of my family members have had terrible luck with their partners, and some of them are once or twice divorced; again, the divorces weren't over simple things, nor were they amicable. Toxic patterns of lying, cheating, manipulation, and even borderline violence were the problem, and in the end, splitting up was the only solution for their mental health and their physical integrity. I've seen what a bad partner can do to someone, and I've become pretty good at spotting the couples who should definitely be breaking up.
If a partner makes you feel unsure about your relationship, is inconsistent, manipulative, has no consideration for your feelings, and their recurrent tactic is to play the victim even when they make you suffer, it's time to run the heck away from them. Sometimes breaking up will be enough. But with some others, a little payback for all they did to you may even help you get closure. I'm not saying that getting revenge is always the course of action, but every now and then, it's not even revenge: it's just them reaping the consequences of their actions. And that's what happened to this terrible ex-boyfriend who had no consideration for his girlfriend's feelings.