Reviewed in the United States on September 30, 2021
"Dumb" refers to the main character, who does dumb stuff from start to finish. He even tells himself "I should do such and such, but I can't help doing this other stupid thing". And he does it a lot.
Dumber refers to the society, government, and military commanders of the future. There is a war going on with an alien race and it's going very badly, but somehow this news is kept from the general public even though the author tells us that they can't hide the number of soldiers that never return home. On top of that, the government is now so desperate for cannon fodder that they are conscripting anybody with a traffic violation into the military. But somehow everybody still thinks the war is going well and will soon be over.
The military leadership is way past dumb. Statistics show that 200 humans die in battle for every alien that is killed, and then they send 9000 marines to battle 800 aliens. That means that after all 9000 marines are dead only 45 aliens will have been killed. Does this make any kind of sense to you?
There is much more dumb stuff going on that I won't repeat here, but trust me, it's there.
The author sometimes contradicts himself, or repeats himself, such as saying "Humanity was advancing by leaps and bounds" and then in the next paragraph tells us "Human technology was advancing by leaps and bounds". He gives us all kinds of new words, without explanations of course, some of which will still be meaningless to the reader after reading the entire book.
And he includes all the standard trope regarding future tech, and if you spend just 30 seconds thinking about any of these you realize how silly they are: - hover vehicles (hey, at least they don't have flying cars) - brain-wipes for serious crimes, because it is more humane to kill a criminal by erasing his personality and memories and then reprogram his brain with a fake personality. Probably saves money too. - laser wands are used by ground personnel to direct landing aircraft (and blind pilots in the holding pattern) - the author thinks light-years is a measurement of time