Good question! It does seem unnecessary, especially since most major conferences record every talk and make them freely available online. PyCon has been doing this for many years, and are so good at it that the talks are available online shortly after they are finished! So there’s no real penalty for waiting until you can watch it online.
I suppose that if you look at tech conferences as simply dry tutorials on some new tool or technique, the answer would be “no, you should save your money and watch the sessions at home”. But there are much bigger benefits to attending a conference than just the knowledge available at the talks. I like to think of it as pressing the restart button on my thinking as a developer. By taking advantage of these additional avenues of learning, I come away with a different perspective on things: new tools, new ways of using existing tools, different approaches to solving development issues, and so much more that is intangible. Limiting yourself to the tangible resources of a conference means that you’re missing out. So what are these intangible things?
One of the most important is meeting people. Not so much to build your social network, but more to expand your understanding of different approaches to development. The people there may be strangers, but you know that you have at least one thing in common with them, so it’s easy to start conversations. I’ve been to 14 PyCons, and at lunch I make it a point to sit at tables where I don’t know anyone, and ask the people there “So what do you use Python for?”. Invariably they use it in ways that I had never thought about, or to solve problems that I had never worked on. The conversation can then move on to “Where are you from?”; people usually love to brag about their home town, and you might learn a few interesting things about a place you’ve never been to. Many people also go out to dinner in groups, usually with people who know each other, but I always try to look for people who are alone, and invite them to join our group.
Another major benefit of attending in person is what is known as the “hallway track”. These are the unscheduled discussions that occur in the hallways between sessions; sometimes they are a continuation of discussions that were held in a previous talk, and other times they are simply a bunch of people exchanging ideas. Some of the best technical takeaways I’ve gotten from conferences have come from these hallway discussions. When you’ve been to as many PyCons as I have, there are many people I run into who I haven’t seen since the last PyCon, and we can catch up on what’s new in each other’s lives and careers. Like the lunchtime table discussions, these are opportunities to learn about techniques and approaches that are different than what you regularly do.
Closely related to the above is the “bar track”. Most conferences have a main hotel for attendees, and in the evening you can find lots of people hanging out in the bar. The discussions there tend to have a bit less technical content, for obvious reasons, but I’ve been part of some very technical discussions where the participants are all on their third beer or so. But even if you don’t drink alcohol, you can certainly enjoy hanging out with your fellow developers in the evening. Or, of course, you can use that time to recharge your mental batteries.
Yet another opportunity at a conference is to enhance your career. There is usually some form of formal recruiting; if you’re looking for a change of career, this can be a valuable place to start. I’ve heard some managers say that they won’t send their developers to conferences because they are afraid that someone will hire them; it makes you wonder why they think their developers are not happy with their current job! But even if you’re not looking to make a career move at the moment, establishing relationships with others in your field can come in handy in the future if your job suddenly disappears. You can also learn what companies are looking for skills that match yours; I was surprised to learn that companies as diverse as Disney, Capital One, Yelp, and Bloomberg are all looking for Python talent. As an example, back at PyCon 2016 I met with some people recruiting for DataRobot, and while I didn’t pursue things then, they made a good impression on me. When I was looking for a change last year and got a LinkedIn message from a recruiter at DataRobot, I remembered them well, and this time I followed up, with the result that I’m now happily employed by DataRobot!
Unfortunately, I’ve seen people who arrive to a conference with a group of co-workers, attend the sessions, eat with each other at lunch, and then go out to dinner together. By isolating themselves and confining their learning to the scheduled talks, they are missing out on the most valuable part of attending a conference: interacting with your community, and sharing knowledge with your peers. If this sounds like you, I would advise you to try out some of the things I’ve mentioned here. I’m sure you will find that your conference experience is greatly improved!