Apple's was actually super late to the nvme storage party, and they're not even remotely at the top wrt maximum write/read bandwidth compared to pcie Gen 5 m.2 ssds you can buy for ~$200-300/TB.
So yeah, Apple's ssds cost at least 3x (and perform measurably worse). And I might add: gen 5 is already what, 1 1/2 yrs old now?
I'm not sure what you're talking about here, because Apple was one of the first PC OEMs to adopt PCIe storage, and very quickly followed that up with a transition to NVMe. This was circa 2015. They just didn't use the M.2 connector, and when they introduced the T2 chip they stopped using third-party SSDs in favor of their own built-in NVMe SSD controller.
Also, I don't think PCIe gen5 SSDs are being shipped in laptops yet (at least not in any significant volume), on account of the extra speed being completely not worth the power cost. Much like the transition from gen3 to gen4, availability of SSDs that are only suitable for desktops with large heatsinks comes long before availability of reasonably-efficient SSD controllers. Eg. Samsung's PM9E1 SSD for PC OEMs only started mass production a month ago: https://news.samsung.com/global/samsung-starts-mass-producti...
[0] from IDT, later sold to PMC-Sierra, then Microsemi, now Microchip's Flashtec product line
[1] Samsung XS1715 was at least the first to pass compliance testing at UNH-IOL
[2] Intel rebranded their enterprise NVMe drives as the Intel SSD 750 marketed for PC enthusiasts, but the real beginning of consumer NVMe was Samsung's SM951 when they started transitioning away from PCIe AHCI (used for compatibility with systems lacking NVMe-aware drivers and firmware).