Neither marriage nor singlehood guarantee happiness.

Many married people are miserable and angry because their marriage is unsatisfactory. Yet many single people are enjoying full and satisfying life. Yet of course many married people are happy and fulfilled.

And for those who think that marriage brings financial stability: many married people, with kids or not, live their life in poverty and find themselves destitute in old age. Either because they relied on their spouses and their spouses didn’t provide what they hoped for or other reasons. Yet many single people build a wonderful life for themselves (and for their children if they have them).

It’s all about how you live your life, either single or married.
You can be happy with either arrangement. Or equally miserable with both.