In addition, there's also a very clear contradiction in their statement, specifically how they "often don’t really need something that fast" but yet they will continue paying happily for Prime. Maybe they only care about the other Prime services and not the shipping?

Amazon, when considering whether to raise the price of prime, probably gathered a lot of information about how consumers would respond. Matte_black’s experience mirrors my own.

When I order something from Prime with 2-day shipping, it’s sometimes late, and sometimes shows up the next morning. It’s fast enough on average that I feel the price is easily worth it. If I really need something ASAP I’ll pay the extra few dollars for the one-day shipping (which would cost a lot more without Prime).

They’d have to raise the price a lot more to lose me as a customer. If there are a lot of customers like me and matte_black, it makes sense for them to raise the price.

By the way, if you do complain about late packages, they will give you a month of free Prime for each complaint or even put $10 as a credit in your account. So if it’s worth your time to complain, you could get Prime for free. It’s kind of like cloud provider who breaks SLA.