I wish they would make the mainstream CPUs offer more PCI express lanes. What is sad is that they are providing boards with multiple m.2slots but all of them require some compromise to use.
Soma boards will take a few lanes from the CPU, thus forcing your video card to run at X8 speed, while others may run off of the chipset, but share the equivalent of an X4 link with the X1 slots, as well as the sound card, USB ports, Ethernet ports, and SATA ports, thus any activity on any of those devices, directly reduces the throughput of your NVMe SSD (e.g., if you have a 970 pro, and play an mp3 from a different drive, you will notice that the soundcard will directly lower the throughput. same with the Ethernet port, or a SATA port.
With that in mind, they need to start offering at least 24 PCI express lanes so that a basic setup of a decent NVMe SSD, a few hard drives on the SATA ports, a PCI-E GPU, and probably 1 or 2 PCI-E X1 devices, all without having to deal with performance being crippled.