I was an RA in college, and also was a residential hall director in graduate school (selected and supervised RAs). My two sisters-in-law were/are both also RAs (one is still in college and is an RA now, and the other has graduated), and a good deal of my friends work in residential life as professionals or have worked as RAs or hall directors before.
My biggest piece of advice is that if a student primarily wants to do it for the monetary compensation…don’t. It’s not that it can’t be a motivator; it just shouldn’t be the primary one. In my experience, those are always the most unhappy students - often they feel quite trapped because when they want to quit, they feel like leaving would let their family down by significantly increasing the costs of college. (I had one RA who really needed to quit - she was in that grey area where I kind of wanted to let her go but didn’t really have a good reason to other than just generally subpar work, and frankly it was obvious that she didn’t want to be an RA anymore and she basically admitted as much. But when I tried to gently coach her out, she didn’t want to quit primarily because of the financial motivations. She was quite clearly miserable, though, and had a hard rest of the year.)
To answer the question at home, this depends entirely on the student, their other commitments, and how much they want to be an RA for the sake of the duties. Most of my RAs became one because they considered being an RA to be PART of the enjoyment and social life of college, not taking away from it. (In fact, I would be a bit skeptical of an RA who came in with the idea that being an RA subtracted, rather than added, from their enjoyment of college.) They enjoyed having residents. Not that they loved all parts of the job - some of my RAs hated organizing events but loved connected one-on-one with their residents, for example. But generally they enjoyed most aspects of being a resource and liaison for their residents; they derived a lot of pleasure from the job and sort of viewed it as an “extracurricular plus,” if you will.
The main components of the job are typically
-On-duty work - how often you’re on duty for crisis response varies from campus to campus, but this is generally what people think of - holding the phone, responding to noise complaints and emergencies, etc.
-Organizing events - again expectations vary from campus to campus, but a clip of one a month is generally an average expectation. Some can be bigger than others.
-Presence on the hall - a lot of people don’t think about this when they are applying or considering applying, but this is a really big part of the job. We encouraged our RAs to spend as much time on campus and ideally on their floors/in their buildings as possible, so their residents felt like they could usually find them in their room or in the building if they needed help or wanted to chat. My RAs did it differently - some of them had “office hours” a couple times a week where they baked cookies and left their doors open for people to stop by; others just chose a part of their floor every week and knocked on doors and talked to people; some decided to hang out in their lounge for a couple hours each week to be available. But this can be “time-consuming” in the sense that even if you aren’t actively interacting with people or organizing something, you’re also not out exploring the city or hanging out with all your non-hall friends or whatnot. Most good RAs honestly spend more time on their floor and in their building than they do anywhere else on campus.
-Some administrative tasks - like going to meetings, training(!), paperwork, one-on-ones with the RHD, “fundatory” (mandatory bonding events with your team! lol), etc.
There’s also side effects - like being quite tired in your Tuesday 9 am class because you were on duty the night before and didn’t get much sleep…
The emphasis is really that your academic life comes first, and the RA job comes second, and everything else is really after. A potential RA has to be willing to sacrifice in other areas if they are doing too much, and I have warned some of my RAs that they need to drop some other activities or spend less time on them (or not be on exec boards) if they wanted to continue in their position.
I say this not to discourage people from doing it - but because I LOVE residential life. I think it’s such an amazing experience for a young person to have if they are so inclined, but it’s not for everyone. You have to be really prepared for the outlay of time and energy.
and found it to be a great experience. I got to be very good friends with the girls on my floor and still keep in touch with some of them 20 years later! It may be different for boys, but we were all very close. With such great benefits, it is VERY competitive though and I’m sure that has not changed, but like you said, your S may just get his long shot, you never know if you don’t try! I didn’t find it overly time-consuming and it wasn’t hard to keep up with my studies and that was even after I went on to take on an administrative RA position with more responsibility. I loved it and would say it only enhanced my social experience in college and allowed me to make even more friends. (Though it may have helped that I just might have bent a rule or two!) 
It is either appealing to someone, or it’s not.