Apple has done pretty amazing things with the m1. IMO the most unique part is scaling memory bandwidth.
The vast majority of PCs are running 128 bit wide memory, with workstation CPUs like the threadripper (and pro) being the exception, but a VERY small fraction of the market.
The M1 has 128 bit wide 67GB/sec peak (that you'll never see) bandwidth, like most PCs. Upgrade to the Pro and you get 200GB/sec. Max will take you to 400GB/sec, and Ultra takes you to 800GB/sec.
On the Intel (i3, i5, i7, i9) or AMD (ryzen r3, r5, r7, r9) you get ... the same memory bandwidth. Check the 8 core vs 16 core scaling numbers and for most benchmarks you'll see poor scaling. Sure you can increase GPU performance by adding GPUs, which reduces (but not removes) the need for extra memory bandwidth. Sadly iGPUs (outside the XboxX and PS5) largely stink and are only good enough for non-GPU intensive workloads. Apple on the other hand does scale GPU performance, granted not to the levels that AMD and Nvidia do.
So why can't anyone in the PC space do more memory bandwidth and a decent iGPU, especially when for years the GPUs were in short supply and had exorbitant prices. I think it does come down to OS support, volume (which could be problematic if current GPU customers avoid you), and potentially reducing profits for AMD (who would have sold an expensive external GPU). Not to mention that fast/wide ram requires soldering chips on board or increasing size/cost with large banks of ram. Even servers with 8 memory channels (minimum 8 dimms) only get you to the M1 pro level (1/2 of the m1 max and 1/4th of the m1 ultra).
Apple can say we have X% of the market today, and all new customers will be on our new platform with 2 years, so the driver, OS, iGPU, memory bandwidth, etc will be amortized over substantial volumes. Additionally Apple gets a larger fraction of the revenue, since they aren't paying Nvidia or AMD for a GPU. Who is going to push a MBP or Apple studio competitor that could ship the same volumes?