Apple themselves don't do component level repair. Why do you think those "tools, manuals" even exist.
Apple does not do component level repair because they want to push new devices and at reluctantly sell parts at obscene profit margins. That does not imply component level repair is not economically viable. It only implies that Apple is that sort of dinasour which Silicon Valley is supposed to disrupt.
Ever heard of mailing your phone in for "major repairs"? Why do they need to do 'component level repair at every retail outlet"?
(See https://www.reddit.com/r/apple/comments/acqwut/do_you_know_w... and more recent reporting on CSAT Solutions's incompetence, poor incentives, and very high turnover).
See https://www.reddit.com/r/apple/comments/acqwut/do_you_know_w...