People come for each other
In 2010 I wrote a postcard from 2020, saying all the talk of virtual meetings being the death of the events industry hadn't harmed it but strengthened it. People still turn up for anything worth getting off the couch for.
The first ripple
Anything said on stage can be recorded and summarised within the hour now, so the program on its own isn't why people turn up. They come for each other, to be in the room and to be seen, and for the chats before, between and after the sessions.
The ripple after it
Your event does the hard work of getting everyone into the one room, and then the deal, the learning or the joining can happen somewhere else, so the room is full while renewals and sponsor returns quietly thin out.
Your immediate future
I'd have a go at saying in one sentence what someone gets from your room that a recording can't give them. Then count how many minutes of your 2027 program go to that, compared with content they could watch at home.
I wrote about this in Postcard from the Future: Events 2020 (August 2010).