The fight was the "object" of massive fan attention.
The fight was the "subject" of massive fan attention.
Which is the correct way to say the fight got a lot of attention between the given choices? The internet tells me it's the first one.
This is an area where there's been significant change over time...
But actually, using "object" instead of "subject" in such contexts was always a bit odd, given that we never had any significant tendency to do that with debate, which is near-synonymous in this context...
As you saw from the Internet, people usually pay attention to an "object". Here is a comparison from Google ngrams.
"Subject" more often refers to a topic of discussion, study, etc. For example, if two people are debating, then we might ask about the "subject" of their debate. Here is another comparison.
There can be overlap. For example, a particular plant or animal species might be either the "object" or the "subject" of a biologist's study.