Bootcamp on Intel Macs was a different story because Apple's hardware was mostly an assortment of other vendors' hardware (with some custom components and set up). That means they could bundle drivers for Intel, AMD, Nvidia, Broadcom, Realtek, Marvell, Synaptics, etc plus a couple of their own (the camera, the touchpad, the mouse, etc) and call it a day. Since the hardware was x86-64 it mostly just worked. That's an immensely different world from their custom hardware. They would need to write Linux drivers for all of their networking chips, each of their processors, their GPUs, work around Linux/Windows' 16KB memory page issues, their neural engines, the SEP, their DCP, the interrupt controller, IOMMU, their custom storage drivers, etc. You're vastly underselling or misunderstanding the size of the situation.

They were also in a different place back when they made Bootcamp. They were fighting a "Mac vs PC" battle head on and trying to convert other OS users to macOS. Now they don't really seem to care about that because their strategy is converting iPhone users into ecosystem members.