I still use them. You can get cheap PCI cards, and for many tasks they are good enough. I used to use a PCI Intel NIC (board has cheap one), but they I swapped it out for an eSATA card, which I actually no longer use. Most people use them for sound cards. For many cheap motherboards, a $30 Asus sound card is a great investment. I still have an old HT OMEGA Claro sound card that I use. It is PCI.I find it very surprising to find PCI slots on a board from an upcoming generation. I haven't had any on a board for the past two, especially on a high end board.
I guess it is cool if you need it but very few do these days.
Also I just noticed, the top end board does say "AMD Crossfire" next to the top PCIe lane so I would assume it does support CFX.
That's not correct. There are 16 lanes running from the CPU, and up to 20 additional lanes running from the chipset (note however that using all 20 of those lanes would mean no SATA.The Lane layout is like this
20 Lane PCIE 3.0
or 16x GPU with 4 lanes for NVME storage