The quality of streaming conference talks has improved a ton, to the point where it’s now really worthwhile to watch them, albeit not the same as being there. Our graduate students and I have been getting together and watching some of the talks from the soiree of the season, the MSRI perfectoid spaces conference. This has been great and I highly recommend it.
One good thing about watching at home is that you can stop the stream whenever anybody has a question, or whenever you want to expand on a point made by the speaker! We usually spend 90-100 minutes to watch an hour talk. One amusing phenomenon: when we have a question or don’t understand something, we stop and talk it out. Then, when we start the stream again, we usually see that the speaker has also stopped, because someone in the audience has asked the same question. This is very reassuring to the graduate students! What’s confusing to us is invariably also confusing to someone else, even to Brian Conrad, because we decided to always presume that the unseen, unheard questioner was Brian, which is pretty safe, right? (One time we could sort of hear the question and I’m pretty sure it was Akshay, though.)