Field repair by enterprise IT support was also part of Lenovo's business model. For framework repairability is a thing but it's not as important I guess.
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.