What "was useful" ? Knowledge?

It means that some of the acquired knowledge was not useful.
The sentence was a little bit awkward.





David

Thank you.

Make it fluent then, please.

The sentence says:

You could lower the threshold, but at a certain point you’d have more knowledge than was useful. "more information than was useful" means "more knowledge than was needed or required". The phrase " more than" conveys the idea of excess.

I could slaughter a cow, but I'd have more meat than was useful. I could buy a barrel of beer, but I'd have more beer than was necessary. You could set light to some gasoline, but you'd have more heat than was desired.

The author's comment could possibly be better understood as

"We had more data than was useful"
"We had more material than we needed"