Ask HN: Is there a shortage of talent at early-stage deep-tech startups?

For context, I’m a student interested in maximizing my marginal positive impact. One career path I’m considering is becoming an early-stage employee at a deep-tech startup working on an important societal problem. In general, my concern is replaceability: if deep-tech startups generally have more qualified applicants than positions, my marginal contribution might be negligible because another similarly capable person would likely take the job anyway. Is this generally true, however? I.e., do early-stage deep-tech startups generally have an oversupply or shortage of qualified applicants? My cursory impression from looking online is that there is an oversupply of recent graduates but a shortage of experienced or specialized engineers. However, perhaps this is completely wrong, so would be grateful for any evidence supporting or contradicting this assessment. Would also appreciate any general insights on whether joining an early-stage deep-tech startup is indeed a high-marginal-impact career path.