My experience
sharply differs and that was also on a T420 (later a T420s, same difference). In my experience there is a
very narrow usage where ChromeOS does not suffice but Linux desktop does. If you fall into this -- and no doubt a lot of people do -- then things are peachy. But step aside and you are toast.
I worked for a company running a certain F5 VPN and their 2FA didn't have a Linux client. I managed to make it work by running an ancient Firefox which still could run old style extensions -- and ran it as root. Very secure.
MFC devices break all the time.
And so forth.