The claim that "Superman is too strong to have any meaningful conflict" is a ridiculous statement and makes the assumption that all conflict is rooted in violence.
Superman has conflicts around philosophy, societal issues, loneliness, balancing work and personal life, human empathy, rescue and yes, he does fight things. Things that are as strong as him. Just because he can move fast and punch good doesn't mean he can't have anxiety.
Source: Superman Lost #2 by Christian Rosado and Lee Weeks












