Startup recruiting trends

Are small- to mid-size startups generally changing how they do recruitment? I am a student who has interned at a fairly well-known yet small company before, and during my search for something similar this year, people seem to genuinely think that that experience is really valuable. I pretty much always get several rounds of interviews, but even after acing them in half the allotted time and getting along well with the interviewer, I simply get automated emails indicating they wouldn't like to continue with the interview process. The only explanation I can think of is that the field of applicants is so deep that they can pick and choose from vastly overqualified candidates (although I would still be confused at their initial enthusiasm about my past experience). Is startup recruiting now getting just as competitive as the big tech companies, or is there something else I'm missing? Are startups doing hundreds of interviews to fill 1 or 2 positions?