I too don't get this transition to working on laptops. What a crappy form factor. I do have two of them - and they get used about 2 hours per month on average.
If you add external monitors, keyboard and mouse you just recreated non-mobile work environment that costs more money and has worse performance than workstation.
A non-mobile work environment, but unplug one cord and you can take the laptop part to meetings, including offsite, you can travel with it, work from the coffee shop or roof or park, keep working if there's work being done on your office (painting or whatever) so you can't be in there at the moment, if you usually work in a corporate office but WFH some days you still have the same machine, can take it to co-workers' desks to show them stuff without having to screen-share and having both workstations together at once, which can be nice in some situations. Built in UPS is sometimes handy, too—no power-offs because you kicked a cord.
I'm not arguing against desktops for people who like them but this "I don't understand laptops" stuff (several posts, not just this one) is bizarre.
This site is just becoming ridiculous. You understand what a portable device is right? That you can UNPLUG the laptop from the external monitor and still use it.
But you do understand that owning a desktop does not preclude also owning a laptop, right?
I have a desktop, and a laptop used as a thin client. The laptop can be inexpensive or have nice features (like a touchscreen), while the real power, storage, etc, is on the desktop.
Not often you see someone use their own argument against themselves. Why buy a desktop with a thin client laptop (that are not in anyway cheap) when you could just buy a standalone laptop.
This isn't even an argument, the decades of the laptops continued popularity say enough.
My machine is way too valuable to risk traveling with is the primary reason. Another is that laptops are noisy due to fans.
My desktop is just a host for several VMs. If I actually need to travel with one of those "computers", I just shut down the VM and copy it's image from my NAS to my laptop.
If you are still buying a laptop for your stated reason, then you haven't embraced virtualization as a developer.
But I really don't get your point about form factor. Using, external monitors and adding a keyboard and mouse to a laptop is a non-issue.