I'm still waiting on my current, 60 hours of use a week, mid-2019 MacBook Pro to die or have any sort of malfunction so I can justify buying a new one. Its battery life has seen better days but that's basically it.
Surface Pro 4 had broken OpenGL driver. Every software that requires OpenGL (basically all CAD software) crashes on it. Microsoft has all the incentive to cripple OpenGL. A generic Intel graphic driver cannot even be installed on surface. You have to use the Microsoft supplied one. Never bought a single surface again.
The cherry on top of the unreliability is the high price of repairs. Even battery replacement runs around $400 for a Surface Pro, while a MacBook Pro battery replacement costs $250
Other anecdote, I cycle-toured for a year camping in all kind of uncomfortable places, and my Surface Pro 7 survived. The screen is cracked in a million places from getting smashed around with all my other kit, but it still works. The Type Cover is a bit crap, though. After going through one of them while on the road (PowerToys Keyboard Manager is your friend) now I've been living in an apartment with a roof and everything, and another one died from what I can only assume to be humidity. I gave up and switched to a cheap bluetooth keyboard instead, which kinda feels more cool and futuristic anyway.
Build Quality refers to how well a piece of equipment has been made [1]. The Surface's tablet has a sleek design with a great construction, uses quality materials and a quality finish that feels like a slab of luxury aluminum and glass in your hand.
In contrast poor build quality would be a thick piece of cheap plastic that creeks and rattles to touch.
Meanwhile, all my Thinkpads and MacBooks still work today.