What you understand about Bitcoin (via BTC) is wrong. I know, I know, this might not be what you want to hear. But certain things continue to happen in the background that are going to change what's popular, but not true. If you're a fan of "the truth", this will be important to take note of. Important to question your own assumptions based on who you've been 'learning' from. For a hint of why, just Google "IPv6 blockchain bitcoin".
Bitcoin could always scale, but politics got in the way and caused it to lose its main branding to BTC many moons ago. Bitcoin (in its original design) can even do everything Ethereum does now, but failed to due to... again, politics. But if you strip away the branding and hype, and look at what BTC can ACTUALLY do currently, is it THAT innovative? Can it do more than 7txps? Can it do micropayments at one hundredth of a cent? If it can't, then all you have left is a shell of what is truly possible. And that should be enough to tell you about its "utility".
No, Lightning Network is not innovative. It is not doing anything inherently new. It is a solution to a self-imposed limitation, that is not necessary, but one that people will buy into if they're not truly aware of what's going on.
Decentralization cannot be a goal in and of itself, because there is no clear definition of what is "decentralized enough." Everyone has a different answer. Decentralization is also about power. Those who don't have it, want to see it removed. But those who have it, will want to keep it. In Bitcoin, there's also been confusion around which part is meant to be "decentralized" - is it peers? Is it miners? Which one are the "nodes"? "Decentralized" for decentralization sake is anarchy, and most people do not want that.
So let me assure you, Bitcoin never left. It's always been there. Hidden in plain sight, ready to re-emerge at the right time. Watch this space over the next 10-15 years.