I don't think it's necessary to attend conferences just to have an idea or knowledge about Bitcoin. It's just a second option, in my opinion. There are many ways we can learn to understand Bitcoin. I have been in this field for several years, and I have never once attended any bitcoin conferences.
Because this is not practical in my opinion, for those who just want to attend, there is no problem. We can learn self-study, and most people here in the forum know that. But I agree with DCA because it is a really effective way to save Bitcoin or crypto.
Everyone has their own way according to their habits and preferences for things, some people prefer to interact directly with fellow Bitcoin fans by attending meetings or joining a community in the real world, but some people don't really want to interact directly with fellow Bitcoin enthusiasts they don't know.
In fact, I myself also feel that participating in meetings or conferences like that is less effective, I self have never participated in a Bitcoin meeting or community in the real world, so far I have only been limited to sharing and exchanging ideas with friends who are close to me also a fan of crypto and Bitcoin. I don't know, maybe because I think attending a meeting is boring, especially if the meeting asks us to pay.
Yes, for me learning independently through reading online articles and following the Bitcointalk forum and learning from my friends who are also Bitcoin fans is more effective and more fun because we can set the time whenever we want, we can talk freely and exchange ideas about the world of Bitcoin.