2011 Lenovo Thinkpad X220 daily user here. Really nice machine really for my needs, running the latest Debian smoothly. I do have a spare ready to take over if needed. Old hardware could always die very suddenly. It's a frugal solution, both cheaper and more ecological than buying new.
About dying suddenly; that goes, in my experience, far more for new hardware. Old hardware (especially if we are talking ‘ancient’ hardware like before 1995) has a lot more signs of giving up and a lot easier ways of fixing it when it does. I have machines that dies that first started smoking so you could pinpoint what component gave out. The x220 is not quite that old but because I have a stack of spares but one favorite, I have been able to fix it after it suddenly died quite easily without just replacing the entire thing. That will not happen when your 2018 mbp suddenly dies.