This is wrong on almost every point, this is a glib and superficial understanding of geopolitics.
Sanctions are a tool - nobody expects them to necessarily 'cause a regime' do collapse.
+ Sanctions were an important part of driving the Soviet Union to collapse.
+ "So really we're just starving North Koreans for literally no reason. " - no - we are 'sanctioning' North Korea to keep them in box.
Sanctions on North Korea are very effective at keeping them powerless.
+ Russia, again your analysis is glib and false. Sanctions are effective - they stop Russian from obtaining certain materials, they hollow out the budget faster, make it more difficult for them to fight.
If Russia were not sanctioned, it's possible they might have overwhelmed Ukraine already.
If you were paying attention, you'd see that Russia is actually showing strain, economically and socially.
Just three days ago Putin signalled the 'war coming to an end' and used conciliatory language when referring to Zelensky.
This is a big shift (among a few others) and sanctions have been a primary tool to coerce his regime.
"Russia has always been 3 weeks from failing" is just nonsense you've made up.
+ "Whatever Iranians think of their leadership, they despise the US and Israel more"
It's irrelevant because the US is not invading and if the regime stops paying them, their anger will be against the regime.
+ "status of the US dollar as a reserve currency are all unravelling"
Again, uninformed hyperbole. USD has strengthened, bond yields are up - those are different things.
+ "Trump has never restrained Israel" - is also false, use Google. Trump defies Israel often, but most critically, the 'deal on offer' that seems to be coming out of the White House would be a 'very bad deal' for Israel.
Trump is throwing Israel under the bus as we speak, by offering Iran fairly good terms, it's why in the last 2 days you've seen Republicans come out on TV to reinforce how Trump should 'seek a strong deal'.
Summary: the sanctions are effective, and the best tool to coerce the regime in Iran, which is horrible, and it will be extremely bad for everyone.
All of that notwithstanding none of this should have happened in the first place.
You read far too much Reddit.