PCIe NVMe SSD on PCIe slot-Worth it?

Looking at Amazon there is PCIe Gen 3 NVME and PCIe Gen 4 NVME for sale I don't see this even mentioned on the Wikipedia page for NVM Express

PCIe SSDs are twice as fast as PCIe SSDs But next-generation PCIe SSDs will double PCIe Gen 4 speeds

genie jackpots slot 5 Place that in PCIe slot 4 which is a PCIe generation 3 slot with x8 electrical lanes The card is PCIe3 x4 Note that the

genie 168 slot Looking at Amazon there is PCIe Gen 3 NVME and PCIe Gen 4 NVME for sale I don't see this even mentioned on the Wikipedia page for NVM Express