Note that the framework isn't completely open source, it runs an Intel CPU so it's by definition running a proprietary blob.
When it comes to MNT, this guy went as far as reverse engineering all SD card drivers, writing his own HID drivers, writing his own display drivers, implememting u-boot support for flashing the BIOS etc.
Look at his github profile, it's kind of insane how he never gives up. [1]
It's pretty serious in terms of being able to claim it's 100% open. I mean, even the batteries are standard ̶L̶i̶-̶I̶o̶n̶ 18650 LiFePO4 cells that can be replaced without soldering or anything. [2]
Whereas with the Framework it's basically "just get a new mainboard" the very same as Apple's laptops are "repaired" these days, which I think is a shame...and they could've gotten much much further if they really wanted to.
In terms of practicality though, it's always the RISC vs Intel debate. Different markets, different expectations.