What I know is from my own life in BDSM. I enjoy taking care of people in my life. I do it well. In my job I am a care giver also. What I get out of being a mistress is being cared for back. I get appreciation, attention and what I miss elsewhere all while being a caregiver in return. I swear, it keeps me sane and able to continue working and being who I am without burning out, becoming resentful and lashing out abusively with my words and actions.
My life as a mistress is pretty much the only area I receive anything in return from others in a way that is tangible. My sub gives me the attention I lack elsewhere in return for the attention I give him. I ask for it, it is given willingly and eagerly. I don't get that on the forum/on line, in my job, from my community. If I asked for some attention in the vanilla world I would get more eye rolls than I get from my son when I try to kiss him good bye at his school
people just don't give in that way on a regular basis. At least in my world. Nor do I expect them to as its not how life works. In D/s subs and doms do though. Its a balance that doesn't exist in day to day life.
What I give to my sub is the release of having to be responsible for their self and their emotions. I take care of all of that for them. I do it because I love them and want to release their burden. Its very cathartic and relieving to be told that you don't have to be responsible, that I will take care of all of that. Its been cathartic for me too to be trusted that much.
I have helped Mono release all kinds of emotions because of the nature of our relationship when I dom him. Of course he can express himself, of course he can do things when he wants and need... Some times what is needed is to be released even from that! A good dom would reckognize when those needs come up (need to go pee, need to remember to send a birthday card to your mum, etc.) and allow/tell their sub to do what is necessary and expected of them beyond the relationship dynamic.