You just explained exactly what a lot of people love about Rio Bravo. It's one of the great hangout movies ever made.Your killing time hanging out with a trio of 1950s icons waiting for them to kill the bad guys ( claude Akins and John Russell) who were killed by the end of every tv western they were in at that time.There was no suspense there, and even though we are comparing both movies, this is why High Noon is better than Bravo.
You find High Noon suspenseful. I find it self-righteous, contemptuous pablum. Tastes vary. We're both entitled to our opinions.