In a PC context as well. It's already possible to put way, way more memory per single DIMM with DDR5 stacked packages than an average user will need. So keeping DIMMs will make mostly sense for server only, and not every of them. Nvidia put 192GB of HBM3 on a package. That's more than what 9 out of 10 mainstream servers have.
And for consumer devices, more integration is always good. I never seen people liking to route super touchy DDR lines by hand. With DDR lanes gone, I think an average laptop motherboard can lose a few layers, get smaller, and use a cheaper material.