As a computer science researcher, I fully agree with your more
negative observations as a PhD. I had the opportunity to go to several
conferences, schools, workshops, I've worked in several non-scientific
projects with industry, using all these activities more or less
naturally to get in touch with a whole bunch of people, mostly other
PhDs, workers from industry, and postdocs and senior academics to a
much smaller extent, though. We discussed ideas (sometimes suggesting
a future collaboration) or just had a nice chat between nice
persons. The outcome for me, however, was that at least 9 out of 10 of
such encounters were surprisingly superficial on the one hand and of
interestingly little professional use on the other. I can say that even after a few years of postdoc.
However, things changed quite rapidly to the positive after my
PhD. Connections made in these years turn out to be significantly more
substantial, lasting, and characterised by a short-term benefit and an
authentic mutual interest people develop for each others' work and
life. As a matter of fact, my existing network largely builds on my
postdoc activities and several years of self-driven initiative.
@xLeitix's answer includes an interesting but perhaps ideal
perspective I was once indeed told and, hence, hoping for to enjoy
when I started out as a PhD. Unfortunately, my experiences differ.
Although I'm still not too long in the business, from several storytellings of senior academics, I grasped that our academic field (computer science,
software engineering) seems to have changed quite a dramatic bit over
the past three to four decades. There are more and much larger
conferences, the publish-or-perish paradigm/philosophy has turned good
parts of the academic discourse into a seemingly ruthless,
non-scientific, and hyper-commercialised rat-race (please, excuse my
slight exaggeration).
An obvious factor driving the structure and utility of your network might
of course be doing research in a trendy field. That, however, can be in
conflict with your personal interests. (E.g., in AI/ML research, you will hit the ravages of time but your efforts might drown quickly in a vast ocean of hardly distinguishable perhaps not even novel
work.)
Overall, networking is undoubtedly key to academic success. But I am
in increasing doubt as to whether the usual regular conferences in our
field are a good networking platform. They often turn out to be
unnecessarily expensive, wasting money that could otherwise be used, for example,
to get good equipment for lab work or even to fund/extend contracts.
Seeing networking as a highly individual thing, my conclusion is: If I
were to do a PhD again, I would have probably tried not to waste too
much time with conferences during my PhD, focus even more on my
research and a few very good publications, attend some schools, and
ramp up my global networking activities only in the last PhD/first
postdoc year. Based on my experience so far, I can thus recommend PhDs (and also postdocs; as already indicated in the other answers) to
- do internships,
- engage in local collaborations within and across the departments,
- spend mobility times (something you should intensify as a postdoc),
- go to smaller workshops,
- visit (summer) schools,
- attend seminars/project meetings, and the like.
There, people get to know each other much more naturally. One thing
not to forget is that as a PhD you are more likely to meet other PhDs
on conferences rather than seniors, they are often far less
approachable. And most of the PhDs won't stay in academia for a whole
bunch of reasons discussed elsewhere. So, the benefit of academic
networking as a PhD is somewhat limited merely because of that fact.