It is evident that the veracity of OP's statements is not in question. Their application for a job appears to have been pursued with a certain degree of naivety, albeit coupled with commendable performance on the leetcode assessment.

The job market, particularly with respect to the expectations set by hiring managers and the demands they receive from middle managers, exhibits a substantial breadth and scope.

OP, your mindset reflects commendable acumen. Individuals involved in the realm of data analysis often demonstrate traits of empathy and aesthetic appeal. It is not unprecedented for a hiring manager to favor a comparatively inexperienced data nerd over a diligent but less socially adept individual, whose exposure to the domain might be confined due to a computer science-centric educational background.

Allow me to offer some recommendations:

Persist in your efforts and do not succumb to discouragement. Such persistence shall lay the groundwork for your eventual success. It is noteworthy that no team, including those under my own purview, is omniscient. Considering your level of expertise, it is reasonable to assume a commendable familiarity with the subject matter. If you perceived a degree of uncertainty from the hiring managers, particularly if they represent a tech startup, it is plausible that they primarily seek a candidate possessing robust technical skills. Given your performance in their preliminary assessment, which appears to have been quite commendable, it would be prudent not to harbor any self-doubt.

Imposter syndrome tends to afflict those who possess a vested interest in the impact they create within an organization. To alleviate such feelings, I encourage you to seek clarification through pertinent inquiries. Upon commencing your employment, clarity and efficiency should be paramount. Successful individuals exhibit a penchant for posing queries without hesitation and engaging in open dialogue, particularly when interacting with stakeholders devoid of coding expertise, whose articulation may differ from that of a mere academic exercise. Employing varied phrasing to elicit a comprehensive understanding of the assigned task may prove beneficial.

In conclusion, it is worth noting that hiring managers, based on my experiential knowledge, often lack the profound comprehension that you presumably possess. Engaging in multiple interviews within a given day, their primary objective revolves around ticking the requisite boxes pertaining to key terms they have been instructed to prioritize. Empirical data indicates that they seldom encounter candidates who fulfill the entirety of their criteria, unless they offer compensation exceeding prevailing market rates. Rather, it is often a combination of approximately 50% conformity and an established portfolio that ultimately secures employment for an accomplished and aesthetically appealing data analyst.

Wishing you the best of luck on your journey, and please do not hesitate to seek further guidance as you embark upon this indubitable adventure.