So, I’m in a long-term relationship with my loving partner, and everything is good, except for the matters of sex. Suffice it to say, one partner (male) has a very overwhelming sexual drive, while the other (female) needs sex like once a month (and it has always been so throughout life). Partners are monogamous and do not explore options of having a third party.
Can any good advice be derived for such cases? Is there something that can be done to improve things on each side? I would love to hear your advice.

That’s tough. Obviously a compromise has to be made, but the problem with compromises is no one is actually happy they’re just less mad.
Are you sure her sex drive really is that much lower? A lot of times, especially with women, sex is not as enjoyable for them because they are trained to be passive and do whatever their partner wants. Why not try talking to her and figure out what she wants. Oftentimes this is difficult because of religious beliefs/purity culture stuff, but keep at it.
Ultimately communication both ways is key. The man needs to tell her his concerns, and she needs to be open with him about what she actually likes/wants.
She does indeed have many blocks in this regard, and that’s something we talked through extensively, although it’s not always easy. She’s willing to have this conversation, but it takes a lot of time to unlearn unhealthy expectations she has formed - including, yes, a desire to please me over herself.
Interestingly, right between this post and your response, we might have (hopefully) found one thing that breaks the ice, so to speak. I’ll see if it can be used to open some more secrets of her deeply buried sexuality…without overstepping much, of course.
But it marks a first time in our long-standing relationship that some key could have been found.