The joke is that guys get turned on by the goth girl aesthetic, but would not actually enjoy hanging out with a goth girl when faced with the reality. The joke works not because there is anything wrong with being a pharmacy tech, but because it paints a picture of the kind of person you would be dating. People immersed in the culture the joke was made in will have intrinsic, perhaps previously unnoticed, associations with this collection of personal details, and the sudden realization combined with the dig at guys' unrealistic fantasies creates humor.

The deeper joke is that actual women who dress in the goth aesthetic are not as appealing as partners as, say, sexy pics on the internet imply. The picture being painted here is the millenial woman who was a goth girl in high school and never changed. It wasn't just a phase, and it turns out, that was a bad thing. It turns out, she isn't actually deep and profound, but just has depression, and used clothing and makeup choices to cover up her lack of an interesting personality. Now more than a decade out of high school, she still hasn't changed, and her worldview and lifestyle are taking their toll. She took a low effort path to get a pharm tech certification, and now works a job that has basically no opportunity for advancement or better pay, but which requires few social skills and lets her dress however she wants. One of her main interests is Invader Zim, a show that had its merits, but which certainly isn't still worth talking about as a regular topic more than a decade after it ended. And with the outline sketched, our mind can fill in the rest of the picture - her, standing with a scoul in her black lipstick and fishnets, the mandatory blue walmart vest clashing with her otherwise all-black aesthetic, holding back a sigh as she waits for a customer to fumble with their phone for 5 minutes to figure out if this is the pharmacy their perscription got sent to. Next back in line, an overweight 57 year old contractor in a RealTree hat leers at her cleavage, which she has mixed feeling about because on one hand, she finds this man's attention disgusting, but on the other, she knows she no longer meets acceptable female beauty standards. A complete lack of exercise, plus lifestyle of staying up late doomscrolling and watching tv while downing canned seltzers with her cats has left her overweight, and looking haggard and prematurely aged. And as she ages out of the goth/punk/emo scene in the mid-sized midwestern city she never bothered to leave, she finds her social circle shrinking more and more - the only people she really interacts with regularly anymore are her coworkers, who dress normal and don't really find her goth aesthetic important or interesting. But she keeps putting on the black lipstick every morning out of habit - since the alternative would be to face the embarassment of admitting to herself that she should have left this phase behind 10 years ago.

It's kind of like the joke that all bodybuilders are losers who work at rental car companies or supplement stores.

Also, this comment should not be taken as any actual condemnation of goth girls. It is just a description of the picture painted by OOP given our larger cultural context. I actually went on a date with a goth-y girl yesterday, and she was fun, sexy, smart, and had a lot of great things happening in her life. But no big tiddies 😭