Heungseon Daewongun's isolationist policy was extremely rational

At that time, the West was swallowing the entire world into colonies,
and even the Qing Dynasty, which was a superpower, had fallen.
Knowing this clearly,
it would have been madness for Joseon to open its doors to the West.
Unless one was a traitor, there was no way other than isolationism.
You say Japan succeeded?
99% of countries became colonies, and Japan is the only one that succeeded;
that is not an appropriate counterexample.
Furthermore, Japan's modernization was not due to its own strength,
but was largely influenced by major powers like the UK
strategically pushing Japan to serve as an Asian outpost.
If Joseon had opened its ports, it would have been more likely to become
an exploited colony like the Philippines, rather than following the Japanese model.
Joseon did not have the same strong unity as Japan,
nor did it have a history of capitalism,
nor had it introduced Western civilization hundreds of years prior.
The prevalence of the ignorant claim that isolationism is unconditionally bad
is because history has been written strictly from a Western-centric perspective of the victors.