What I noticed about the bio-tech VCs is that they commonly have some actual expertise in bio-tech, e.g., in their educations, frequently MDs, bio-medical Ph.D.

What I noticed about the bio-tech VCs is that they commonly have some actual expertise in bio-tech, e.g., in their educations, frequently MDs, bio-medical Ph.D.'s, or both, and good, relevant technical experience before becoming VCs. So, a guess is that with such backgrounds, the bio-tech VCs can look at a bio-tech startup and look at its technology and actually understand and evaluate it, understand the competitive situation, look at market potential, evaluate the technical qualifications of the founders, etc. E.g., for bio-tech projects, the NIH problem sponsors can do such evaluations. For STEM projects, the NSF, DARPA, ONR, etc. problem sponsors can do such evaluations. The corresponding situation for information technology VCs is wildly different -- history majors who got MBA degrees and have some experience in business development. With high irony, it was leading edge STEM field technical work for US national security and the space race that initially got Silicon Valley going -- transistors, microwave, radar, etc.