Statements like these frustrate me, because they paint a picture as though Ethereum is a strict upgrade to Bitcoin, without depicting the many sacrifices that Ethereum has made to get its advantages. The word blockchain in general has completely changed meaning - no longer does it specify systems where there is no trust involved, instead it specifies systems that create a high interoperability between money and applications.
There's a huge difference in the security and decentralization model of Bitcoin and Ethereum. Bitcoin has no central leadership, actively rejects the pursuance of one, and works hard to build a network that simply can't be attacked.
Ethereum on the other hand has a powerful central leadership, and moves faster and does things that are in general far less secure. When they hit road bumps like the DAO attack, the 'Spurious Dragon' chain split, or other major network events, they fall back on their central leadership to resolve the issue quickly.
That's really not decentralized, and it's completely different from the vision that Bitcoin originally painted. It's a completely valid model, and it's a step up from using a fully centralized platform like the Google Cloud, but ultimately the Ethereum foundation and surrounding leadership has the ability to push through controversial changes, something that is strictly rejected by the Bitcoin philosophy. It's also not clear what will happen if someone like the US Government leans into the Ethereum Foundation asking for things like capital controls. Bitcoin doesn't have a leadership for the government to lean into - it's going to be a lot harder to add captial controls to Bitcoin than to Ethereum. Depending on who you are, that's either an advantage or a disadvantage, but at the very least it's a very clear distinguisher.
For that reason, Bitcoin is far more interesting to me as a technology. It's the first and really only, technology that allowed something like a monetary system to stand completely independent of a leadership or a governance structure. Ethereum hasn't achieved the same thing, that much is made obvious by the fact alone that they don't know what the core consensus algorithm of the network will be in 18 months (maybe it will switch to a yet-undefined Proof-of-Stake, maybe not).
Don't get me wrong. Ethereum is doing interesting things. They've completely changed the way people thing about money and applications, and made it possible to apply money to everything. But it's far less secure, and it Ethereum today simply wouldn't work without its central leadership. To me, that makes it not much different from any other technology out there - its giving us new and more efficient ways to do things that we have already been doing.
But anybody who thinks that Ethereum is a strict upgrade to Bitcoin has completely missed the point, because Ethereum does not have the core value proposition that Bitcoin provides. Bitcoin is a complete financial system that you can use without needing to trust anybody. Not the developers, not the miners, not the government. Bitcoin is extremely impressive, and definitely is a technology in a class of its own.