However, we're talking about Chevy parts compared to a Mercedes S Class (CT6's competitive set) and you have to keep that in perspective.
Well, for that matter, the S-Class interior, for the price, does not particularly impress me....neither does its very thin exterior sheet metal. What the S-Class
DOES have, though (and I'll be the first to admit it) is superb chassis and powertrain engineering.
Chevy interiors were so bad for so long - and quite frankly, they still are probably bottom third in the market - that saying they have improved isn't really much of a qualifier.
You're correct that they were junk for years, but, with all due respect, I think you underestimate the recent ones.
GM tends to use a basic, all caps, early 90-s looking font that's white and too small relative to the size of a button- on every button on an interior. Ford does the same thing. The Asians and Germans quite simply understand that these details matter. Make nice buttons for a Camry and you might be able to use some of them in an ES or RX. Chevy's buttons are ugly no matter what they're in, which just makes them even more out of line when stacked up against an A8 or S Class.
Chevy buttons and switchgear seem to vary quite a bit from one model vehicle to the other. In the Sonic, for example, they actually use motorcycle-type gauges/layout....not the case with other Chevys. But, since we were (ultimately) talking about the Cadillac XT5 , I'll have to pass further judgement until actually see what kind of switchgear is in it. If I think you're right, I'll be the first one to agree.
(I'll say one thing, though, right off the bat. I definitely don't like those finger-slide sensor-controls for fan speed, radio volume, cabin-temperature, etc....that both Cadillac and Lincoln have used for several years. Lincoln has partly corrected this in the MKC, with some (not all) of the functions gong back to rotary-dials).
A typical example of those finger-slide/sensor controls is found in the Lincoln MKZ: