The thinkpads are good. Dell has a good lineup of laptops that support ubuntu right from the factory. XPS line would be my bet and if you want more business leaning laptops the Latitude series.

I would _not_ recommend Thinkpad CX1(gen6). It works but has a number of problems despite being Ubuntu Certified. Like trackpad and trackpoint not working / funny, fingerprint scanner, overheating, or closing the laptop lid. An older Thinkpad may be a better choice.

As asked for thinkpad;s alternative: HP ZBook https://store.hp.com/us/en/mlp/laptops/workstation-352501--1

I looked at these, expecting the "alternative operating systems" to be maybe Ubuntu, but shocked ticsee a FreeDOS offering

The FreeDOS option is basically the option to not pay for Windows ($229 for Windows 10 Professional, $197 for Windows 10 Home).

Purism laptops might also fit the described need https://puri.sm/products/librem-13/

Entroware (UK) company builds linux-supported laptops / PCs.

Any System 76 laptop

Thanks, I didn't know them.

BTW: The first online store for notebooks i see that isn't filled with tons of javascript and overlays and all the stuff. That alone is a reason to buy one from them.