The "panel lottery" is still a thing, especially from the major brands like HP, Lenovo, and Dell. They don't say what you are going to get, they change panel suppliers without changing the model number, and in general they don't give a damn about how the thing looks. I guess it's why people buy Apple.
I don't know about Lenovo and Dell, but for HP, they do say what you're getting.
I'm not familiar with the Z Book line, but for the Elite and Pro Book (which we have at work - it's why I know) they give some specs. Usually, they quote NTSC coverage and backlight intensity. Now, they never say it's great, mind.
I have a top-of-the-line EliteBook screen and while it's very bright, colors aren't great and viewing angles are a bad joke. But that's likely related to the "privacy screen" feature.
One of its cousins has a lower-end screen, which is 6-bit. Its angles are fine, but it's basically unable to display real reds.
The first one was quoted as something like 72% NTSC. I forget what the other one was, but certainly below 50%.
And, indeed, these laptops are not cheap. My 14" EliteBook cost a few hundred euros less than a 14" M1 MBP with the same quantity RAM and SSD (32 / 512). Now I haven't seen the new MBP screens, but my 2013 MBP's screen runs circles around these pieces of crap. Also, battery life is comparable to my 2013 MBP, but the SSD is slower.
Apple at least used to often use multiple suppliers, I remember people saying one was better than the other, maybe somewhere back in the first few generations of laptops with retina displays.
