You know the great thing about the guitar industry is that so many builders are still based in the USA.
Gibson USA, Fender USA / Custom Shop, PRS, Suhr, G&L etc for guitar companies then you have an industry of “boutique” amp builders – Dr Z, Swart, Victoria, Matchless, Milkman, Tone King, VVT, Greer etc and then you have an industry of “boutique” pedal builders – JHS, Earthquaker, Wampler, Keeley, Analogman, Fulltone, Walrus, Xotic etc and then you have an industry of “boutique” pickup builders – Lindy Fralin, Jason Lollar, Throbak, Stephens Design, Sheptone, D Allen etc
Guess what all these companies have in common? They’re all based in the USA, and most of the boutique ones are essentially one man or two man shops. The guitar industry is one of the few industries left where a good portion is still based in America and the manufacturing can still be done in America.
Can’t say that for computers, electronics, phones etc – the infrastructure to manufacturer those devices have long moved out of the USA. If there *was* an American phone maker who actually made their phones in the US, then I would guess it would be quite a bit more expensive than your typical iPhone.
So the answer to your question, the reason American phones in China can considered great quality (Apple, Google Pixel, etc) is because there are no phones made in America to compare to. The reason why American guitars made in Asia are considered inferior is because there is still infrastructure for American made guitars, and thus a chance for companies to market those guitars as being ‘better made’.