Because if Ron and Royce could surpass Clark, it would undoubtedly be a good thing for the current universe. At the very least, Robet would no longer have to fight alone.
And most importantly, because of Robet's unique nature, Ron and Royce were unique as well. They had no need to worry about affecting other versions of themselves in the multiverse, because they were one of a kind across the multiverse.
So Clark decisively handed the newly appeared Doomsday over to the Avengers, Ron, and Royce for practice. With his speed, even if Ron and Royce really proved no match for it, Clark was confident he could save them.
And even with Robet absent, there was still Barry Allen, a wielder of the Speed Force, who could reverse space-time. There was no need to worry about Ron and Royce's safety at all.
Just like that, Clark left with complete peace of mind, without even going over to comfort Connor and Joe, whose moods were also less than wonderful.
The reason Connor and Joe were in poor spirits was simple. Steve's earlier words had also made them feel somewhat uncomfortable.
As the sons of Clark, the most renowned Superman on Earth, Connor and Joe were undoubtedly proud. Even though they had grown up alongside the brothers Ron and Royce, and knew that their uncle Robet was stronger than their father, just not as famous, that pride remained.
But being pulled so far behind by Ron and Royce at such a young age still left Connor and Joe feeling discouraged.
Connor especially had always treated Clark as his goal, wanting to truly inherit Clark's mantle.
Moreover, Connor's strength had once been above Royce's. Even when Royce first caught up to him, there had not been much of a gap between them.
That