No I don't think they are overestimating, the graph just doesn't say what you said it does. It does not count the residences that have access to 2+ options, it only counts the number of houses that lie within census tracts that have 2+ broadband options available anywhere in said tract.
This means that even a residence with literally 0 options would be counted as a "2+ broadband options available" house if there were 2+ broadband options available anywhere in the census tract it lies within.
The numbers don't have to be refuted, they simply aren't numbers that indicate whether there is a problem or not because they answer a different. But unfortunately no, I don't have any data other than this report. I was super disappointed when it came out because I don't know of anything else.
You are right, what the report says is that 97% of people live in census tract where there are two broadband providers. What percent have access to the two is unknown, but absent any evidence to the contrary, and given the relatively small size of census tracts, it is reasonable to assume a majority have access to the providers in their tract. I'm open minded here, show me some data that shows a large group of people don't have access to at least 2 broadband ISPs.
Apartment buildings often make exclusive deals with cable companies for a variety of reasons. And even when they don't, it can be very hard to deploy new infrastructure anyway.
Yes of course, like I've said, the number is overstated, but by how much? How many people in the country live in apartments like you describe? 2%? 5%? 10%? It still doesn't make much of a dent into 97%
This means that even a residence with literally 0 options would be counted as a "2+ broadband options available" house if there were 2+ broadband options available anywhere in the census tract it lies within.
The numbers don't have to be refuted, they simply aren't numbers that indicate whether there is a problem or not because they answer a different. But unfortunately no, I don't have any data other than this report. I was super disappointed when it came out because I don't know of anything else.