I personally have found some fantastic growth in playing in these areas, but you are right. It is not for the faint of heart and it requires tremendous vulnerability and constant communication.
Given how men and women are wired differently, IMO (and biased with a male POV) men benefit more from this, since society creates a harsh environment for women over their entire arc of their life.
That doesn't mean men don't have the same issues, but it does have an effect differently based upon the age and time when sexual engagement occurs.
If you haven't read my erotica poetry, you will see I actually write the walk I have done in my past life and current life. I have found the practice for myself personally a very rewarding one. This is due to some advanced trauma I had and how I used "self-love" to protect me.
Now that I am healed in a lot of areas (and not in some mind you), I still play with this. Let me tell you, as I age it expands my sexuality in ways that is downright awesome.
For couples or close friends, it can actually help one. another. I am of the belief women need constant and more orgasms on a regular basis to help bolster their confidence and self worth (in a positive way). Should they need this and only this (of course not), but frankly the hormones between the two genders are slightly different. Women from my random readings that I have done over the past few decades and based upon hands-on, actually gain better dopamine and other aspects which increases their drive and feelings, men need to hold off because the drop-off after orgasm is very severe. So if a guy can keep near and above the 90% engagement, he can gain a lot of benefits from heightened senses while not having the drop off.
The thing is, this means he/they (in the manner of a couple), need to make sure that the guy is always being touched and edged a bit while being denied.
It may seem like insanity but repetition will teach the man better self control, and also given the practices will teach pleasure that is more female centric (i.e. is a whole body experience). In a couple setting, that means a female partner should feel lots of foreplay, oral and toys to get her happy moments. Then he could engage, and even do penetration but he must learn to control it. It is also a great way to work with consent. E.g. May I have intimacy with you, kiss you, take your clothes off, touch areas of your body, pleasure you, insert myself in you, thrust in ... and then of course at last .... orgasm and release.
The woman should feel strong and confident to say no, and this is important, because it enhances the love and trust and respect. No means no. If the male partner can control himself it sends a powerful message to his female partner that she can trust him all the way.
Folks may say gee that is a lot of work, but honestly if you are a feminist and believe and love in women. Why not go that extra mile to make that person feel safe and empowered and in control.
The real reality as men age and women do the same, men will need more foreplay and this practice will do nothing but help.
So for a couple, a fun game would be this ... every day the couple roles a die, and the number that comes up is the goal of the number of orgasms that the couple will try in a day.
Then try to make it so the guy gets the last orgasm (so you better have a 3 or higher. What a fun way to fix the orgasm gap :)