Inconsistent writing and a lack of sense of scale on the writers part. Toriyama has stated he doesn’t think much about the weight statistics he gives for anything. Goku during the 23 Tenkaichi Budokai explained his weighted clothes weighed a hundred kilograms. That is a lot of weight and it would require super strength to move, but Goku had early sent a small car flying into the air and pushed a giant boulder. A hundred kilograms to him should be nothing.
Or there was him supposedly considered two ton weights to good for training in his base form by the Buu saga, four weights for a total of eight tons. When Goku was training under a hundred times normal, his body would weigh more than eight tons. Not to mention the fact that he showed he was strong enough to hurt beings who can tank planet destroying explosions.
This lack of any sense of scale continues in Super. Goku was supposedly hit enhanced gravity akin to a black hole and it did no real damage, only threatened to push him through the ring in the Tournament of Power. If he is strong enough to take gravity like that, he should be able to lift a thousand tons with his finger.
Now don’t jump down Dragon Ball’s throat for a lack of sense of scale because almost every franchise you can think of tends to suffer from it. It’s just that Dragon Ball has a habit of giving numbers that are far too small.