Macbook Neo is manufactured with leftover / binned A18 Pro iPhone chips, these chips have a defective GPU Core and Apple was sitting on millions of these. Apple does not have an easy way to dispose of these chips, the base iPads use 2 generations old A16 chips & the iPad pros use M series chips. So they created a new product line.

The Macbook Neo is cheap because the CPU/GPU/Memory chip is sold below cost. The Neo line exists to dispose of / repurpose binned A18 Pro chips and when these run out Apple will significantly raise prices.

This is the identical situation to what happened with the original Raspberry Pi, the Pi company acquired leftover Broadcom BCM2835 chips for almost nothing, and were able to sell Raspberry Pis for an impossibly cheap price of $35.

All of these, and more. Macbook Neos benefit from all the hardware that Apple makes in-house, reusing CPUs that they already make for iPhones but didn't make the cut, have zero upgradeability, benefit from massive economies of scale, contracts are already signed in advance, the delivery and logistics of an existing chain...

Framework has to go talk to Intel and AMD, get parts shipped, assembled onto a motherboard that they have to make themselves and ordered in very low amounts then shipped all to their fulfillment center, then fedexed, have to source components... Even not taking into account the fact that Apple already has all of the hardware made or available in-house, just the supply and logistics chain is an easy 10% of the final price.

Efficiencies of scale and experience, on multiple levels.

Component sourcing is the most obvious thing - Apple is known to buy up inventory years in advance for example and at insane quantities. TSMC's last new node? Apple paid billions to be the initial and, most importantly, exclusive customer. With hundreds of billions of dollars in cash and liquid assets, Apple can afford to sit on "dead money" for years - a small shop like Framework can't.

As for the Neo specifically, this thing shouldn't even exist, but Apple found themselves sitting on a stash of half defective iPhone SoCs. But instead of trashing them, they effectively recreated the netbook market segment...