My 2 cents are that the Sun, the vitality and the inner authority of the person, is ruled by Saturn queen of duty, which is exhalted in Libra just because it does so well accepting social constructs (such as the need for relationships and balance and peace in order to thrive in the physical dimension) which are obviously a needed part of our experience. I feel Libra to be as much of a karmic sign as Capricorn, after all, they are both Cardinal signs, where action and manifestation is emphasized and thus fear has an opportunity to become quite pronounced. Not to villainize Saturn any more than it already perhaps justly perhaps unjustly is, but because it is such a karmically aware, "outerly" focused planet, a person with a Saturn-ruled Sun may abandon their own fulfillment, the hardest part being they feel on a deep level of their psyche that it is the only correct way to be, and may struggle to liberate themselves from that belief just because it is integrated so deeply on multiple layers of themselves. The Sun is also linked to pride so the person struggles with pride being linked to work and physical proof of their worth.
Physical manifestation is a crucial aspect of fulfillment on Earth. But my opinion is that when it is focused upon in such a way that psychology, spirit, fulfillment, emotions, human contact, etc., all come last... that's a pretty hard life. It's hard because we've abandonned our desires, and thus ourselves, and the things that actually keep us going and missed the point that physical manifestation is nothing but a result of those things, and not the other way around.
SSOOO when a Capricorn gets depressed (since we're focusing on Cappy here; and only the shadow aspects mind you; there is also so much that is wonderful about Capricorn as it is with all signs - I own my Capricorn in both my Western and Vedic astrology) and misses the first 2 hours of work, if they have abandonned themselves as described above, all they can do is focus on labels. Exterior labels. "I could have gotten to work on time but I didn't therefore I suck". And that attracts more sucky experiences. The heaviness of duty can create so much anxiety, that the ego is invited to the driver's seat to deal with these emergency situations that have everything to do with survival and avoiding self-punishment and often little to do with true happiness. From here it becomes easy to totally disconnect from Source, the source of inspiration, bigger picture thinking, love and thus self-compassion, etc. So a Capricorn manifesting failure or unhappiness in their lives has an intuitive sense, as any human would, that they are creating what is in their environment (especially since Capricorn is integrity) but they may struggle to understand how to stop the downward spiral, as they have been conditionned to devalue their internal guidance system, or emotional compass (more for Cap Moon), or whatever you want to call it, and personal happiness, and replace it with fearful rules (I feel like where there are rules there is fear, because there is a lack of trust) and "tangible" goals. Since their source of self esteem is so tied up in these, as their ability to be of service begins to break down, or as they can no longer ignore how empty they feel inside, they may turn to substances to cope.
Really it's a symptom of a lack of self-awareness and respect for their personal desires. (!!! But these are lessons, not end points. This is not fate people, this is fate in learning. !!!)
I want to share this video here because I feel ideas expressed in it are very liberating to the aspects of Capricorn energy that are experienced more pleasantly, such as pure, uncluttered ambition:
https://www.youtube.com/watch?v=aoYJSQPkuw8
If you're referring to Capricorns born around the early 90s, they have draconic Pisces stelliums, so there's the additional element of being much more connected to the divine feminine and not so for such a ruthless, competitive, fast-moving society, you could say. This receptive creative energy, if supressed and not allowed to flow, can manifest as the need to escape. And the irony is a Capricorn, by virtue of being a Cardinal sign, is more concerned with physical action steps, perceiving them as more practical, and so may not always be ready to hear about needing to embrace a state of receptivity. Is a nice way to put it. It's hard for me because I also know that some Capricorns, by virtue of striving and struggling, do become very spiritually focused. But to break down a wall there must be a wall and that's how it starts. Edit: This actually brings me to another point: Capricorn IS a feminine sign. It NEEDS inspiration, it needs purpose, it needs receptivity in order to be plugged into its priorities. Efficiency requires receptivity.
Lastly, I wanted to point out in Vedic astrology most Capricorns are Sagittarians. This ties in with wanting something more than what is sensed society, and thus the present moment, provides. So there is an energy of craving freedom on a soul level and striving for the impossible dream, ultimate fulfillment... that would also lead to emptiness and addiction (edit: and perhaps a sense of entitled "wrecklessness") if not realized. It's funny because adjacent signs become a lot less contradictory when you dig into them

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Edit: I don't see females wouldn't be affected in this way too, but perhaps in females the cycle manifests more in terms of striving for perfection or things such as eating disorders, because smoking and alcoholism is a little more societally taboo for them? Or perhaps females do a better job of embracing their feminine sides and feel a little less pressure with regards to physical achievement or unconditionally exercising their left brains.