Untrue. The ludicrous circumstances I provided have come close to happening. There have been cases where someone had sex with an underage girl found in a 21+ bar where the guy who had sex with her saw her ID.
Some states have provisions to protect statutory rapists who were defrauded by fake ID. It's going to fall on the jury to determine whether the defendant had reasonable proof to believe the partner was of age. It isn't strict liability everywhere. Criminal law always has the question of culpable mental state. You mentioned traffic violations... how can one possibly argue they had no idea they were speeding? There are speed limits statewide for when roads have no posted limits, and equipment (speedometer) failure falls squarely as the driver's responsibility.
And for the record, Ohio's consent is 16. I know people say there are 13-year-olds who look 18, but I've never personally seen that.