Framework laptops aren't really repairable in the same way that old Thinkpads are. Maybe that's good, maybe not, but replacing an entire motherboard every 3 years isn't all that different from replacing an entire computer really.
Also, you don't change its motherboard, you change the mainboard (for my laptop, it's the CPU/integrated GPU + memory sockets); this is unlike changing the entire computer. Then, you can reuse the replaced mainboard as a server if you wish to.
This pales with my experience using a Macbook Air whose motherboard failed. I did have to replace the entire computer.
IBM HMMs, or creatively named Hardware Maintenance Manuals, were written so that if all steps in the document were performed from start to end as written, the laptop would be a pile of FRUs or Field Replacement Units, so that those FRUs can be inspected, discarded, ordered, and replaced, and then the process can be done in reverse to produce a working unit.
Why - I mean I think I know why - they likely don't have enough control and/or influence over parts suppliers to be able to publicly expose those data unlike the Big Blue - but why...
0: https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/...
I had an HP that also had service manuals available.
Ps Lenovo basically has two brands; the business laptops like the T, P and X ThinkPads, and the consumer stuff including some of the budget ThinkPads (I think E series). The latter don't do service manuals, have really crappy keyboards.. Just B-brand crap. They're just a consumer laptop with some thinkpad trim. Be careful with that if you think of buying one.