What's so appealing about married man in dating site/app?

It is quite often for me to find men that put “married man” label as part of their introductory profile. I, myself, have never dated a such a person nor have I had any conversation regarding why they’re flaunting that status in online dating site/app. They also stated that they are looking for sex/dating.

I suspect that people who put this label are the types that willing to give ‘reward’ for sex, or perhaps they’re simply being honest with their status? I mean, realistically, who would want to date someone that is already in marriage relationship. I could be wrong. What do you think? What are the typical reasons for men to put their “married man” status on online dating sites/apps?