Lab-leak was a sensational "whodunnit" and the entire purpose of promoting it (true or not) was to distract from the far more important "what should we do about the pandemic." The people pushing for this distraction A. wanted to do nothing (economy in an election year) and B. once they realized that doing nothing was unwise, needed to cover for having pushed A too hard, with too many "aged like milk" statements and actions. It was the public health policy equivalent of shouting "look, a squirrel!" Re-focusing the narrative away from the squirrel and back onto the pandemic wasn't only not sinister, it was a gigantic face-palm that it had to be done in the first place.

That's also why interest evaporated: the two real reasons to push the story both expired in 2020. Now all that remains is idle curiosity. As far as I'm concerned: indulge. Go nuts. Now that you aren't worsening a public health crisis by pushing an election agenda, it really is just a fun little detective story, and I'm as curious as the next guy.