I don’t know about now, but the old AJPW & NJPW rings looked pretty rigid.
Some rings are designed that way, while promoters sometimes use a boxing ring (which is a lot more rigid, but they probably got a good deal on) and dress it up like a wreslting ring.
The Fed switched over to much harder rings as part of a deal with NBC execs to carry SNME in the 80’s.
Vince had them switched back when he concluded that too many of his talent were getting hurt too often.
This was shortly after Foley’s fall through the “Cell.”
i remember reading something about that and much stiffer the WWF rings were for guys coming in from other feds.