Care to explain that statement? I always thought Marvel's Superman was Thor (Strength, Flight, Cape, not from Earth, but feels as tho they're Earth's protector)
Sorry for the delay...
Reed is Superman's "equivalent" NOT on a power basis, but as far as their role, position an importance in their respective universes.
Both Reed and Superman are the most important heroes of their respective universes. No other hero can claim the same level of impact, influence, track record and focus point for their respective universe. They ALWAYS save the day, no matter what. The Marvel Earth would literally no longer exist if it specifically wasn't for Reed Richards, no other hero would have been able to stop Galactus, and in every universe Reed doesn't exist in, it ultimately ends up dying. Superman is the same fashion for DC as he is a Nexus being and the DCU's existence is due in major part to his presence.
Thor is often considered Superman's equal but its kind of a fallacy. Thor isn't and never was Earth's #1 protector or their first line of defense in the same way Superman and Reed (and FF by proxy) have been.