I am still trying to understand what you mean by the internet being centralized, if you’re referring to all these companies like Google, Facebook, and Amazon as you have said, then you’re completely wrong. And by the way, Amazon has nothing to do with controlling the internet, it’s just an online shopping platform and nothing else.
Facebook is a social media platform and they will only be focusing on that and nothing else. Google is just a search engine like Yahoo, Bing, Yandex, etc. These people don’t control the internet, they just help you reach the content you need. If it was able for them to control the internet and control Bitcoin, then the government would have started up similar platforms and their first targets would even be the dark web and not even Bitcoin, because there are lots of weird things going on there than you can imagine.
It's true that the aforementioned companies don't control the Internet in their entirety. But technically they do, since their services are indispensable within cyber space. A person cannot live nowadays without using Google, Facebook, or even Amazon. One fact is that Amazon also provides cloud services (storage, web hosting, etc), which are not limited only to e-commerce. Considering that most people don't care about using centralized services which steal their utmost sensitive information, decentralizing the whole Internet would be quite a difficult (if not impossible) task to achieve.
Bitcoin may be decentralized by design, but it still depends on the centralized public Internet for transaction broadcasting. While you could say anyone can use privacy solutions like Tor & VPN, these same solutions are not 100% anonymous. If you become the target of ISPs and the government, it'll be difficult to use Bitcoin without getting noticed. That's why we need a decentralized Internet infrastructure in order to maintain the Bitcoin blockchain as resilient as possible. After all, Bitcoin full node operators are subject to different governments' regulations.
Nonetheless, the implementation of satellites, radio waves, and even mesh networks may be the first step to further decentralized the way we access the Bitcoin blockchain. But a lot of hard work needs to be done in order to provide a perfect solution that would resist the opposition of worldwide governments and ISPs. Just my thoughts