I'd agree with that, I run stock ubuntu on a thinkpad t460p. I have only one issue which is that display scaling is not fractional, its in set values which doesn't play well with resolutions above 1080p. Thats a gnome issue though and doesn't stop the screen working perfectly when the resolution is set to 1080p instead of 2550x1440 or whatever it is.
This is trivial to fix actually. Ubuntu 16.04 had "fractional" scaling by default but in reality all it did was between 1x and 2x use 1x with larger fonts. 18.04 lost that with the gnome transition but you can just change the font scaling manually. Less convenient and polished but still there in the tweak tool. Firefox also includes a scaling option in the configs. With those two settings my T460s with the 2560x1440 screen looks great. It does suck that the Gnome transition in the new LTS has been so bad. For all its quirks the Unity on Xorg experience was actually very stable and polished for years now.
This, right here, is an excellent case-in-point illustration of the reason Linux isn't widely used on laptops: even on expensive, high end hardware with excellent Linux support, and the most popular distribution, very basic functionality like screen resolution not only doesn't "just work" out of the box -- getting it to work properly at all requires serendipitously stumbling across a random forum post somewhere that directs you to the needle-in-the-haystack magic config file tweak that makes it work properly.
I'm running linux (manjaro - kde) on my thinkpad T470. It works marvelous, scaling works without issue, adding screens, updating, hibernate/sleep. It all just works.
Currently haven't rebooted my laptop for 45 days, updated in the middle (while still being able to work) and still works wihout issue.
Meanwhile my windows desktop keeps forcing updates/reboots every week interrupting my work.
Also interesting to mention: windows always has the fans on of my laptop, on linux only under heavy load.
Bought the laptop especially for the linux support on the thinkpad series, very happy with it.
Googling for the issue would get you the source where I got it from, so it's not as bad as you claim. And up to 16.04 the last few years of Ubuntu LTS releases have been smooth sailing in my experience. In 18.04 they did a transition into GNOME3 as the default and that's still showing the issues that showed up. Unity was actually quite polished and functional.
But let's not blow this out of proportion. It's not like Apple has not had plenty of QA issues with OSX lately. But I agree Linux desktop QA could use some more resources. Unfortunately it seems the Ubuntu desktop/mobile push is mostly over and they're now focusing on server/container where Linux has been great for a long time already. And since volunteers always prefer writing new shiny stuff than spending time doing QA the Linux desktop will probably never be extremely polished. I do find it much better than Windows and comparable or better than OSX in actual functionality for us technical types but your mileage may vary.
FWIW I do the same as suggested and it's great, font scaling set to 1.4 on a 14"@2560x1440 T470P running @2560x1440 looks nice, the only very slight snag is that font scaling doesn't scale the window decorations but a few themes do work (Numix window decorations).
I believe it applies to all screens. I've only been using external screens to project stuff fullscreen so I haven't checked what happens if I use my 1920x1200 screen as a work screen. If it's like in Unity you get the larger fonts but it's still quite usable. Having the font scaling be per-screen would be ideal though.
What’s the battery life like compared to windows? I have the t460p running w10 with the extended battery and I’ve never run out of power in the middle of a workday. It would be painful to give that up, but at the same time I’m interested in running linux as main OS.
