I appreciate what you’re saying but I doubt many would have any difficulty engaging a cross bolt safety placed at the rear of the trigger guard like an 870. At the front edge of the trigger guard? Well, that’s a bad design and necessitates you removing your hand.
As for cross bolts not being used on major systems? I disagree, cross bolt safeties are used on a lot of full auto only small arms to this day. Likely because they are cheap and robust, although most date from the 70s as you mentioned.
As I said, a rotating safety, while perhaps more user friendly, are not needed on an arm that only has one mode (be it semi or full) of operation. I’m certainly used to the AR15 safety and have no issues with it but one could also make the argument that on a semi auto sporting rifle that cross bolt safety is just as effective and arguably more ambi friendly.
Of course saying all this I then look at the Benelli MR1 which has all the ergonomics of a brick in your hand. You can’t do anything in that rifle without removing your dominant hand from the grip.