That’s more than the weld, and it’s a good thing the safety pins are designed to secure the inside and outside dual square tubing together. Often that’s from one of two things, 1) a tongue that hasn’t been lubricated and bolts rust lock, 2) an extended hitch camper towing. Using 3’ extenders, on overhead bed campers, seems to just wreck the tongue from flexing consistently while towing.
Also, if you are not the original owner, then you have no knowledge of what anyone did prior to you. If they tried to free up a rusted tongue, then who knows as we have seen a lot of damage passed on second hand. Everything from hammered on to forced open with out working lubricants into the rusted joints. The pivot bolts were changed to high grade stainless, though even then that stainless gets frozen in rusting steel.
just stay proactive on lubricating your tongues and watch them if you run, or someone else has, an extended trailer hitch arm.