Way back in history long long before the 'arch' came along as a concept (as a much better solution for spanning window and door openings in ancient buildings ) masons had to quarry and shape long heavy lintel stones and then hoist these huge rocks up into position very carefully.
The span of the openings couldn't be very wide because of stone's inherent weak tensile strength as a building material. They might break with their own weight and come tumbling down.
Designs for stone structures back then must have been very limited. The ancient lintel-itects had no idea that a wonderful new age was to dawn with the Roman invention of the arch.
Things must have been very different before those arch-attachers came along.
Let's try to consider what that archless world might have looked like.