People don't want to quickly turn their phone into a desktop, they want to quickly turn their phone into a laptop. Apple's laptops are over 75% of its sales. And if you have the screen and keyboard of a laptop, why not put a CPU, battery et al. in there?

I think you are missing the point. People don't want to turn anything into anything. They want a minimal number of devices covering all their needs.

then I guess we'll have to wait for companies like huawei with their mate xt, or more likely given friendshoring, the samsung trifold to give people phones that turn into tablets and have a companion keyboard for them to feel this is enough of a threat to address