This feels a little like a decade-old maxim that needs a refresh. Most comparisons that I find of modern flagship handsets against even mid-range point-and-shoots show the dedicated cameras failing to dominate. Particularly with computational processing it gets really tough to honestly just wave a hand and scoff at the mobile as a primary choice for most casual photo situations (and some professional, as well!)
I too love my manual-operation DSLRs and mirrorless swappable cameras, and just bought a new lens for my go-to. But I've not found myself in years compelled to spend what I'd need to on a pocket camera that'd beat what my phone can do.