In earlier years, the energy efficient "Ultra Low Voltage" CPUs of the U series hardly offered any performance, but manufacturers still packed them into workstation laptops. Even though the modern U processors are still considerably slower than H CPUs, at this point their absolute performance is high enough for new models such as the ThinkPad P15s Gen 2 to be able to deliver sufficient power for CAD applications.
https://www.notebookcheck.net/Lenovo-ThinkPad-P15s-G2-Workstations-with-ULV-CPUs-are-getting-better-and-better.545955.0.html
I read the title, and think the "ulv cpu" is ryzen U. But not. So sad :'(
I have had several Thinkpads for about 15 years, most of them "Mobile Workstations." I do a lot with Rhino 3D, and a lot with Photoshop, as well as other science and image processing programs, such as Paraview and ImageJ. I've also used FEM and CFD. Yesterday, I was using PhotoShop, to re-chop up Blue Marble Next-Gen for a friend who is working on a simulation, an image that's 86,400 x 21,200, that takes over 14GB of memory.
Generally, low-spec machines are still not fast enough for doing design work and heavy-hitting programs. The likely are good for programming, where moderate hardware will do. I'm glad that they are made, but please be sensible of their capabilities.
For on-the-go design or even reverse engineering, once you are carrying a 15' computer, it might as be powerful enough to do the job. The lower power processors would make more sense on a 14" computer, and allow it to have a proper GPU, but we don't usually see that, such as an RTX Quadro 4000 in a 14" laptop, which would be useful--unless you need to raytrace something. Well, maybe the GPU could help--if it has enough memory.
A smaller computer can be useful for reverse engineering, because, you need room on your work bench for measuring tools--in addition to the computer.
What would make it more interesting: putting a low-power CPU with a fast GPU, but I've not seem many of those options. ; )