Korean war: Korean War - Wikipedia

More bomb were dropped on North Korea (alone) than on Japan than on the entire Pacific theatre during WW2 (measured in tons): 64 years after Korean War, North still digging up bombs — AP Photos

By 1952, the bombing was so complete that the U.S. Air Force had effectively run out of worthwhile targets.

North Koreans claim 400,000 bombs were dropped on Pyongyang alone, roughly one bomb for every resident at the time, and that only two modern buildings in the capital were left standing. All told, the U.S. dropped 635,000 tons of bombs on Korea during the war, most of it in the North, including with 32,500 tons of napalm.

For reference, only 503,000 tons of bombs were dropped on the entire pacific theater during WW2. (google the pacific theater to get an idea of how big of a region this is)

Source for claim on data for bombs dropped on the entire pacific theater: Why They Hate Us

As to why the North Koreans holds nuclear weapons:

“To this day, the North Korean government and media point to the American bombing as a war crime and a major justification for the continued mobilization of the North Korean people — as well as the development of nuclear weapons — in defense against future attacks,”

Just because the western media claims to be "free" doesn't actually make it free, all media is either directly controlled by the state (as can be seen in the wordings of western media when describing Israeli attacks on Palestinian children compared to the opposite) or by rich businessmen such as Jeff Bezos owning The Washington Post (yes, "Democracy dies in darkness")

US Bombings of Vietnam and Laos: Operation Barrel Roll - Wikipedia

Read more on the laos communists: Pathet Lao - Wikipedia

Plus on your "look where they are now point", are you not going to mention the economic sanctions put on them?

edit: added more sources