Why do modern motherboards have so few PCIE slots?

Why do modern motherboards have so few PCIE slots? what does pcie slot look like Meanwhile ever since all this happened my PC would randomly freeze requiring a restart, in either slot with every config like 2-4 what is a slot diffuser And the CPUChipsets do not have enough available PCIE lanes for this to make much sense anyway Things like USB4 controllers, 10Gb

what is a slot diffuser And does all x16 lane PCIe slots are of the same size? which is look like it spans the entire x16 slot dimensions If it doesn't

what is a pcie x1 slot used for The traditional Mini PCI slot , the full height Mini PCIe slot , and the half height Mini PCIe slot The Mini PCI cards What kind of form factor are you looking at, if you are going for stuff like mini-itx case there's like only enough space for 1 PCIE slot