No automobile is engineered to be easy to work on.
They're all engineered to be assembled efficiently. That's job one.
If you buy a car for the long run like I do ease of access to major components is something to consider. It will effect the cost of maintenance.
Beyond that...it's luck of the draw.
Only variant would be when manufacturers cram to much motor in too small a engine bay.
Funny story....Back in the day I had a beater '71' Dodge Dart.
It needed a carb rebuild. I did it myself (those were the days LOL) cost of rebuild kit...$17 bucks.
My boss and very good friend had a 73 Mercedes coupe (similar technology). cost of rebuild kit...over 300 bucks!!!!
Just for the hardware. I rebuild that one too.
(Hey, that's what friends are for).
One more thing to keep in mind when you invariably find that vintage exotic for a price tooo good to pass up.
A "Chevy" is a lot cheaper to maintain than a BMW.
Theirs no free lunch!