I do a lot of embedded C++ work and byte stream work where packing matters, but I agree with you. For most development it’s irrelevant, and in the future I expect it to be even less relevant.

But I feel like over the last ~10 years there's been a trend back towards learning more about them (e.g., with Rust and new C# features, or with C++ Win32 programming becoming a cool hipster thing somehow)? Or maybe that's just my own personal bubble.