While Facebook has stopped showing event attendees in most cases, LinkedIn has started doing so, for our benefit.
LinkedIn has just introduced Event search. Pick an event that is of interest to people with whom you would like to connect and mark yourself as “attending”. (Marking means an intention to attend). You can then not only see the full list of attendees but can also search within it by the usual filters like company, title, and location.
As an example, here is, for our Online Sourcing Day 2 on Nov 4, 2020 (which you should attend if sourcing