That is just waaaaayyyy too simplistic.
Is there a certain kind of work and a certain kind of people where socializing with everyone outside the office via fancy dinners and ski trips is critical to having the right connections to get ahead? I'm sure there is.
Are there a ton of jobs and opportunities where blatantly throwing money around just because is not necessary to get ahead? Absolutely.
The key is to find the right environment and people for you. I would argue that if you're not drawn to/comfortable in the world of high-fliers, then it doesn't even matter whether that works for other people, because it won't work for you -- you will need to be inauthentic and play the game, and if that's not a key tool in your toolbox, the others will see you as playing a role and not belonging, and you will not succeed. Find a world that plays to your strengths, not where you need to be someone else to succeed.
I'm a lawyer. I have seen a ton of incredible marketers in action, and have felt completely outclassed and like I could never keep up -- people who go to conferences and come home with 17 new contacts; people who do the high-class wine-and-dine circuit; the one guy who I swear never even got on a plane without coming up with at least one new contact from someone he met on the flight. But you know how the best marketer at the firm does it? He's the smartest person in the room, with the least ego about it; when he meets with clients, he focuses all that ridiculous brainpower on strategizing how to solve their problem; sure, he does the "meet for dinner after" thing, but at normal restaurants that normal people eat at, because that's where the clients are comfortable. You know how the other best marketer at the firm does it? He has spent 30 years trying to help people -- when someone needs a job, he calls on his entire network to help find one; when someone needs a referral, he spends his time tracking down the best one; he remembers (or at least keeps really good notes to remind himself of!) everyone's birthdays and kids' names and medical issues and life events, because he actually cares about them. Oh: and both of those guys drove totally unimpressive cars to boot -- both made close to a million bucks a year, and one drove a big white minivan because he had young kids, while the other drove a 35-yr-old Volvo station wagon.
Apparently DH and I have managed to "network" ok as well, despite a complete lack of a schmooze gene. Know how I got my first client? I had done work with him at another job, and he had remembered that I was wicked sharp, so he called me when he had an issue in my area. I honestly hadn't even remembered the work and had done nothing special to "cultivate" a relationship. Know how DH got a new job -- with a raise and promotion -- after his company shut down? He immediately called and emailed a whole bunch of people he had worked with closely in the past, and they knew he was really smart and did good work, so they were happy to pass along information and recommend him to the Powers That Be who were looking to fill a slot. Oh: and in both cases, the obligatory cement-the-relationship meals involved delicious, cheap burritos and enchiladas at local hole-in-the-walls.
tl;dr: be you, not someone else. Figure out what you do well and enjoy, and work that.