To be honest, that was the opinion I always went with.
Here's my issue: why the fuck does Gohan think someone whom he can parry with one arm in Base has improved so much that he might leave him in the dust soon? I understand pep-talk, but damn. Trunks looked really tired, so an alternative is he wasn't accustomed to getting the most out of Super Saiyan just yet. Gohan wasn't that strong as a Super Saiyan, so naturally his Base wouldn't be much. Super Saiyan Trunks being weaker than his Base makes him literally a trash-tier Super Saiyan.