Does Networking Matter (after you get the interview & other Q’s)?

Alright. So hypothetically, one goes to extreme target (H/Y/P/IU IBW, lol), gets 4.0 in target major, does all the finance clubs & org’s, somehow swindles a soph boutique internship (hypothetically w/ out networking), etc. When said person is applying for IBSA, does he really need a network? Or when he applies to banks via application portals, are all the job posters going to gobble him up and throw him an interview?

Let’s extend this to a mediocre kid. Semi-target, “passable” GPA (3.6-3.8), all the competitive finance clubs & org’s & activities, has some sort of business internship, etc. Obviously, a network would be extremely beneficial. But assuming that he/she passes the HR check and gets the HireVue (would appreciate insight on what the very first steps are prior to technicals interview), to what extent does a network matter? Is it just for getting your foot in the door (I.e. getting the interview) OR does it provide marginal benefit during the interview process?

I ask this because I have connections in banks, but the jobs these people hold aren’t at positions, coverage groups, or locations I want. For example, I have a great connection w/ an MD at EVR/GS/C O&G in HTX, but I’m not fully committed at the prospects of working in O&G or in HTX. Could this connection (considering the seniority level, MD) provide benefit to other offices in different locations and groups, or would I only be leveraging our connection if I were to work for his office? I’m assuming the latter, which is why I’m mildly afraid that I’ll have no connections for jobs that I actually want to work for, considering my “mediocre” profile.