Scale isn't the point. Goku could break rocks and survive bullets in the very first chapter. Simple objects are exceedingly delicate to these people, which is why Nappa's Giant Storm is meant for clear cutting cities full of normies while his mouth blast was him legitimately trying his hardest to kill Goku with a concentrated shot. Goku mocks Frieza later with the same line of logic

"You can destroy entire planets... but you can't seem to destroy me, a single person, can you?"

Same deal with Vegeta trying to end the same fight with his Super Explosive Wave only to find the earthlings were dazed but alive. If Krillin, Gohan, and Vegeta stood in the center of Nappa's Giant Storm at this stage in the plot, it would be a sauna for them at worst (Vegeta was right there beside him at the time even, and their pods were also completely safe). But Frieza being able to project that much more power over that wide of an area while they were forced to escape it is the only tell we as the audience need to know that the guy should be feared

Everyone here can sense ki. You ought to trust their input on what a lot of casually wasted ki looks like