Is it ever okay to talk to an Ex long time after a breakup, does it has more cons than pros?

Yes, I do think it is okay to reconnect with certain exes. While this differs for different situations (abuse), people change, and can grow. You will not be the same person you were 5 years ago, and it wouldn’t be fair to judge you based on a less grown version of yourself. This goes for other people, you might be surprised and happy to learn that they may have matured into a wonderful person, who is good to have in your life. Some of my closest friends are exes whom I have reconnected with over the years, because people grow into better versions of themselves.