yes considering my comments are based on it, feel free to correct what you think I misunderstood.
First of all, routing the CPU lanes to slots would add a lot of cost, as it would require a more advanced PCB layout, PCB and PCIe 5.0 redrivers.
Not impossible, but expensive.
The market trend, for better or worse, is towards more M.2. However, the board layout is based on what the motherboard makers cook up, so if you have an issue, it's them, not AMD's fault.
The chipset has four lanes because of cost. More lanes equals bigger chip, which equals more cost in every single step of the manufacturing process.
Yes, Intel moved to eight, for some of its chipsets. AMD chose a different route, but can clearly move to PCIe 5.0 for the next generation.
PCIe 3.0 is clearly not dead, since each chipset can support four lanes and/or SATA. I guess you didn't read the Gigabyte board news post from Computex, but they use PCIe 3.0 for Ethernet and WiFi.
The B650 boards will be a lot cheaper and if you'd read any of the news posts about upcoming motherboards, you would've known there will be more affordable X670 boards too.
However, PCIe 3.0 will end up being a peripheral interface only moving forward, so get used to it.
So many people seem to misunderstand how PCIe works as well and this isn't directed at you as such, but it's not possible to take eight lanes of PCIe 5.0 and magically make it into 16 lanes of PCIe 4.0, it requires expensive ICs, as PCIe wasn't designed to work in that way. This is why we're getting PCIe 5.0 x16 slots, since if you plonk a PCIe 3.0 graphics card in there, it will end up running at 16 lanes of PCIe 3.0 bandwidth, not four lanes of PCIe 5.0. It would be great if someone could conjure up a cheap chip that would allow this, but sadly, there's no such thing.
85-90% of people never put an add-in card in their computer these days outside of a graphics card. We're a minority, so the motherboard makers are catering to the YouTubers who clearly are going banans for M.2 right now. Maybe go complain to them and things will change, if they change their tunes. (Yes, you pointed this out).
Also, most motherboards come with WiFi and Bluetooth built in these days, so no-one's going to add that.
Most video capture, unless it's for professional use, is USB based these days.
M.2 slots are a lot cheaper in production, as they're added during SMT, whereas through-hole components are added by hand, usually by underpaid workers from the Philippines if the boards are made in Taiwan, or equally underpaid workers from the xinese countryside if the boards are made in xina. Each manual step has a higher cost than something that can be done by a machine. You're confusing market segmentation with actual cost.
This is a bit old now, but I've been to this specific factory some years ago. A bit past the 5:40 mark is where the through hole components are being added, by hand.