PCIe switches weren't common or necessary for most consumer applications. Workstation and server CPUs have plenty of lanes on their own. PCIe switches occupied a relatively narrow use case in the middle where people wanted to use consumer CPUs but attach a lot of add-in cards and share bandwidth across them.
Even that use case has been eroded a bit with PCIe splitting options, where an x16 lane can be split into x8/x8 or even x4/x4/x4/x4 depending on the motherboard. An x4 PCIe 4.0 lane is as fast as an old x16 PCIe 2.0 lane, so that's a significant amount of bandwidth still. PCIe 5.0 takes this even further, where an x16 PCIe 5.0 slot has over 60GB/sec of bandwidth, which is a lot even when divided into x4 or x2 channels.
AMD especially made platforms with a lot of PCIe lanes relatively affordable. An AMD workstation motherboard and CPU with a lot of PCIe lanes might not actually be that much more expensive than a hypothetical consumer CPU with a PCIe switch. The other issue is that with a PCIe switch is that you're still limited to upstream bandwidth, so if you need x16 bandwidth running to multiple cards at the same time, a PCIe switch doesn't actually help you.