There are real functional/usability reasons for having a separate device (with its own compute/storage) in a laptop form factor, and furthermore if we are honest, laptops are a kind of student/professional fashion accessory (especially Macs), a social-signal that you are a "knowledge-worker". As a result, that form factor is not going away anytime soon.
What Google are doing seems less about the "desktop mode" for Android (though that's a necessary technical step) than it is about having a unified consumer OS experience between Android and ChromeOS, which according to reports, they are planning to merge.
Do they? What I want is the power of the desktop available when I have access to it (SW & HW), but if the phone is powerful enough (maybe with a small accelerator box for dGPUs to handle gaming/AI), I’m not really seeing the value of multiple devices; it’s just more clutter and stuff to maintain (e.g. SW context, more HW things that can break & require repair, etc). I’m already using remote VSCode to always program on my home desktop computer regardless where I am because it’s easier than juggling clones across machines and forgetting to sync somewhere.