Originally posted by DarkSaint85
Ahahaha ok. Stilt suggested a guy who was PL 900, and I've of course seen the memes about PLsbeing over 9000 being something amazing, so 18k isn't bad for a soccer mom.
Power levels are essentially a way to measure who is stronger then whom in universe, but otherwise bullshit outside of that context.
For example, in universe Master Roshie very casually blew up the moon. This was within the first chapters of the entire franchise. Goku was like the monkey king from Journey to the West, with an inexplicable monkey tail on him. Being an alien from another world was not an invented concept yet.
Fast forward some 17-18 volumes of rhe franchise, and Akira Toriyama retcons Goku as being an alien from a race of alien conquerors, who bring devices called "Scouters" with them, and the invention of "Power Levels" comes to exist. Master Roshie had a power level of around 180-200. Goku was 400.
Further, Roshie's power level of 180-200 is after much training, meaning he was definitely weaker when he casually dusted a moon in the 21st Budokai against Goku. How much weaker, we have no way of knowing.
So bottom line, Vegeta is the first character to directly threaten the Earth with destruction, at a power level of 18k. This does not mean you need a power level of 18k to destroy the Earth.
All it really means, is Vegeta at 18k is stronger than Goku at over 9 thousand.
The numbers are not a feat, though fans will use the numbers to argue potential feats through multiplications of useless numbers, ala "If Goku can dust a planet here, he can destroy a galaxy here!"
Even though we have no idea what the numbers actually mean, or how they relate to destructive potential. For all we know, a very wide gap of numbers can mean very incremental gains, or vice versa. Or they may mean something else entirely. Smaller numbers HAVE hurt bigger numbers in canon, as much as the fans come up with excuses as to why (He wasn't ready! He was holding back! He was distracted! He was tired!)