Yeah, 5e Wisdom is particularly problematic because it includes two saving throw categories (Will and Perception), while Intelligence is a dump stat.
D&D 4e and 5e made ability scores identical to the saving throws. It makes sense. People who are competent at offense tend to be competent at defense as well.
Even so, the bonuses for defense tend to be different from the bonuses for offense, so each category gets handled separately anyway. So the ability score is more like a general aptitude that tends to influence both of them positively.
Well, depending on the build, there are usually two choices for dump stats for people who want to dump them. For example, while a fighter might not want to dump WIS (to aid in perception and saves), they could just as easily chose CHA as INT for an 8 if they want.
It depend what one means by the English word ‘dexterity’. If one only means ‘manual dexterity’, then it has nothing to do with dodging, little to do with an AC bonus, and is humorously absurd to save against a Fireball.
However, if one means ‘bodily agility’, then people who are highly agile correlate strongly with quick reflexes (autonomic neural response, gross motor skills).
This issue with DEX is it encompasses WAY too much: balance, manual dexterity, agility, reflexes, hand-eye coordination, flexibility, and probably more.
The idea with ability scores in D&D is someone with a high DEX excels at all these things, perhaps to various degrees, but all are strong to some extent.
‘Poor health’ doesnt really make sense in D&D anyway. For example, the Elf traditionally has an epic lifespan − one would assume because of an epic Constitution − but actually tends to have lower Constitution compared to other races. An other example. The D&D 5e death saves are unrelated to Constitution. So even the 1e concept of ‘system shock survival’ no longer exists. The male/female distinction between male upper body strength and female longevity no longer exists in D&D anyway. The concept of health cuts across many D&D mechanics, and is unsystematic.
That said, people who tend to be ‘healthy’ (exercising often, resisting illnesses, healing from injuries) generally tend to be physically stronger than people who are unhealthy.
Having one score for Strength-Constitution means this character is good at melee combat. It is a useful and meaningful number.
The elf physiology cannot be known of course, but I have always thought that "lower" CON was due to their smaller body structure. Their long life is more likely contributed to slower metabolism, etc.
Anyway, we play death saves ARE linked to CON. It is not a CON save, but a CON check since it makes sense that someone with a high CON, robust and healthy, would be more likely to have their body withstand the trauma of injury and self-stabilize. Likewise, a poor CON would be less likely for the body to stabilize due to frailer health, poor diet, etc. (pick your reason really...).
Concepts like system shock are still there, such as the rules for suffering massive damage.
IIRC there was never a distinction between male/female for strength, flexibility, pain tolerance, etc. There should be IMO (say females -2 STR, +1 DEX, +1 CON, or for the female-centric group, males +2 STR, -1 DEX, -1 CON).
But, for example, there are MANY example of strong people, such as a man I work with who I would imagine has a STR 16 or better! would, due to his being very overweight, smoking, and does little cardio, would have a CON 9 or maybe even 8. Likewise, when I ran cross country, I would put my CON around 14, but my STR at 10 at most.
In the idea of a combined STR/CON ability score, how would these people be represented???