If the welding is done right, good but not over penetration and no massive long welds, which should allow the frame to have a little flex, it should be fine.
Back when I was a younger man, in the north east, they made cars and trucks with real frames, not the newer unibodies. If the frame got damaged, you could get a "state certified" welder to repair it. I've seen some ugly repairs, but they held up fine.
OK, my opinion is over.