Is it an OEM part with the same quality as the original? Will AliExpress carry the part 5 years from now? (Framework systems are backward/forward compatible).
If you spilled your drink on your Framework keyboard from your 13" system that you bought 5 years ago and you bought a replacement from Framework, you'd be getting a better and improved model of the keyboard. Same deal with issues like cracked screens, webcams, and batteries - since the original Framework came out, the company has upgraded those parts, and makes them available to people who bought the original system.
AliExpress 3rd party battery replacements are basically never as good as OEM.
That level of support is is unique and you are trying to downplay it as something that other OEM offers, and I think that's a little bit facetious.