Here is my current take on tech conferences. In my opinion, the benefits of attending tech conferences revolve around three main things:
After attending many conferences in the last couple of years, I realised that if you are not into networking and getting to know people in the conference days, then the main benefit of attending is gone. If you would like to learn and get inspired, just watch the talks online. I understand that attending the talk may give you a chance to ask the speaker a question. But this can be done also on Twitter, I believe most speakers are on Twitter and they are happy to answer the questions you have.
I also believe that inspiration can be achieved by watching the talks, DHH and GaryVee inspired me for years by only watching their conference talks but I've never met them in person. It worked for me, I also understand if you met them and talked to them in a conference you may be getting more inspired but not all conferences have the people who inspire you anyway. And to be honest with myself, I would go to a conference just because of some specific speaker are there, but most conferences do not have such speakers all the time.
For networking, this is the main benefit of conferences, you go out there you try to promote your work, find business partners, making deals, make connections with people and companies. So if you want to do networking, conferences are the best place to do so.
Probably, with almost all conferences last year (2020) happened online, this idea of getting the learning and inspiration part became more convincible. You can even argue that networking can be easily done online via social media or online conferences. But I think meeting in person still has its benefits and many people will still go to conferences just because it is fun and to meet new people and visiting new cities. This alone justifies going.