The idea of having that info in one place is great, but I agree that it's not quite accurate. The policies are often a little too nuanced to be represented in a nice chart.
Just took a trip on American Airlines. The sheet say that your bike counts towards your baggage allowance and costs $150. But, depending on the kind of ticket, you don't actually have a baggage allowance. However it does count as your first, checked bag. Every checked bag costs extra, and your second bag costs more than the first, so a boxed bike costs $150, plus it counts as your first, checked bag, so if you check any other luggage, it also costs a little more because of the bicycle. I put mine in an S&S case and brought everything else is a carry on, so it only cost me $50 round trip. However I had to leave some items at home, like my rear rack and my helmet, because they would not fit in my carry on, and a 2nd, checked bag would have added $70 round trip. Checking a bag plus a full-sized, boxed bike would have been $370 round trip, which is why my wife decided to leave her non-coupled bike at home.
Meanwhile, I have a trip on Southwest planned, and they allow two checked bags and only charge $75 for a boxed bike. Looking at the chart, you would think that means they're $75 cheaper than American Airlines, which is true if the only thing you check is your bike. If you check a 2nd bag, though, on Southwest it's free and on American, it's not. Then American ends up being over $100 more each way. For my part, I can put that bike back in the S & S case, and check a 2nd bag, and have no extra baggage fees on Southwest.
So, yeah, the details section is going to be key for making a list like this useful.