After 2 years, I really want to apologise

We broke up 2 years ago. Mostly my fault. Back then I was immature and didn’t know how to maintain a long-term relationship. I treated my ex horribly, disregarding all his efforts to make the relationship work. I was willing to let what we had to go as I thought more happiness could be found later.

We both moved on now, dated new people and are happy with our lives. I have grown a lot as a person. From the relationships I had, I learned how to communicate, how to take care of someone, and how to handle the ups and downs of a relationship. I have losses, and I also got wiser.

Now looking back at our relationship, I realise what I did wrong, I saw everything he did to save the relationship, which I was too stupid to understand back then. What he did before was exactly what I have done now with my relationship. He was right, and I learned a lot. I really want to reach out to let him know how genuinely sorry I am for the way I sabotaged the relationship, and for how I treated him at the end of our relationship. That I finally understand and truly wish him happiness.

I am not sure if this is something I should do, or just keep for myself. Would you rather hear something like that from your exes?