I was never a big fan of live online (research and technical) presentations, lectures or seminars. I'd use pre-recorded online materials when looking into a topic myself, but I was never able to immerse myself to a live online lecture anywhere close to the level of an live in-person lecture.
And this was never a problem. One course during my graduate programme became online-only last minute as the Lecturer decided to go for an academic visit to a different University. I dropped it (wasn't my top choice anyway) and replaced it with something else. On conferences, it was very rare, and every time a talk was delivered online, I could usually find an almost word-by-word pre-recorded version somewhere, and just go through it at my own pace and time.
For the above reasons, I never really considered "following online presentations" as a crucial skill in my academic career. (And my progress reflected that.) I think I can passably give a presentation online myself, but I lose my concentration way faster trying to follow an online presentation than an in-person one. I can identify several reasons for why I find this to be difficult for me:
I can not put my computer away as I'm using it to watch the presentation.
There's no "setting change" between my "work space" and the space where I listen to a talk.
Even with the most comfortable and quality headphones, prolonged listening to presenters (people talking rather than music) on headphones gives me at least a mild headache.
I'm already self-conscious about asking questions, and I don't think I can get them across half as well in writing: they either sound clunky or unclear to me, so I'll avoid asking questions.
And then, enter the global pandemic. Everything shifted online for over a year now, with some very mixed reactions from the community. Some think that online and hybrid approachers "work well". But they really really don't, for me. Up until this point, my attitude was grin and bear it while we have no other choice, and then jump right back into the real, in-person thing when we can (maybe, jump really slowly and carefully at first, through small local events etc...). I think that it was the best possible stop-gap solution, but that it lacks the most valuable part of in-person meetings, which is the unstructured mingling before and after the talks. But more and more people are lauding the great success of hybrid events. So the title question: is the ability to follow online presentations now an essential skill in academia?
While I list the reasons I would find this difficult, I did many difficult things in my life already, especially when I set my mind to it. Note that I'm not looking for advice on how to concentrate during online events -- advice on that has proliferated since the start of the pandemic. I'm not asking if it's "just" useful either -- the ability to do long sums in your head can sure be useful if you're working in maths, but probably not crucial. To avoid sounding like I'm asking for an opinion, I am interested in whether there's any evidence that progress in one's academic career might be severely impacted or impossible without this ability in the post-pandemic research landscape..