Philosophy of science is very relevant and more difficult than ever. But you couldn't do philosophy of quantum mechanics before the science of quantum mechanics. When I say philosophy I mean metaphysics or in general attempts to explain the natural world. A lot of that has been made redundant by science. Not ethics.

Modern scientists don't usually like philosophy and don't write about this stuff from a philosophical point of view. It's more necessary than ever that philosophers get with the program. Pretending that science hasn't taken the lead in explaining the natural world won't help. People like Nick Bostrom who think about what science reveals do, even though he's probably hated in philosophy circles, like Daniel Dennett or Lawrence Krauss are.

Scientists in academia are often ignorant of philosophy; this seems to be a side-effect of increasing specialization and corresponding tunnel vision.

Science as an empirical practice of truth-seeking is reliant on philosophy for its foundations. Of course it is possible to "do science" without having any interest in epistemology, just as it is possible to program computers without having any interest in computer science, or to do mathematics without having any interest in mathematical foundations.