Thank you for this response. You went through options in both sides of the fence and that's something I wanted to hear.

I was considering a PhD in ETH or EPFL. Going deep is mostly what I've been thinking. Actually getting an understanding and contributing to the field is more important to me than just working on something more interesting. My current job is already on something interesting but the actual work I end up doing is on the surface level, often avoiding any kind of innovation to minimize the risk. The time I can spend on learning is also way more limited than what I could get if I was doing dedicated research.

In the end, I'm not sure if I want to end up in academia. It's hard to know if something is a fit without trying. The article you linked is a very helpful sample of what to expect.