This probably has more to do with a power vacuum in which lawlessness arises instead of the ideology that is at power.

But in this case this is not about politics, it's about local power and local control, and Laos government have very little of either of it. Laos communism and Vietnam communism are very similar, but you don't here the same about Vietnam, because Vietnam is easier to control due to geographical terrain and investment by USSR and china after the vietnam war. Laos still have areas with unexploded personal mines and ammunition (the "joke" there is that US pilots couldn't aim for shit, the reality is that vietcongs used Laos jungle path to encircle US soldiers, and so the US made those path unusable). Laos have way less roads, rougher terrain, and mines. You have basically local feudalism. Imagine colombia, but ten time worse.

As opposed to capitalism, which as we all know works flawlessly. The free hand of the market keeps everything running smoothly. There’s always competition for the benefit of the customer, never collusion. There aren’t just a few bit players controlling everything, everyone has equal opportunity. And of course who can forget trickle down economics, where giving more money to the richest people made every one of us richer.

Capitalism’s most outstanding feature is that no matter how hard it tears one’s asshole, it keeps people begging for more with the false promise that they too one day will have their turn as the selfish oppressors doing the pounding, and that’s a good thing for everyone actually, for some reason.

Is there any ideology applied societally at the scale of those two which hasn’t failed to deliver?

this really has little to do with communism. after all the vietnam war etc concluded, that area kind of got left to itself by the powers that be.

It's a small country that was given a political system to be a client-state of a hegemonic regional power, and then the hegemon abandoned them, they don't have valuable resources like crude oil or gold, and they end up with underdeveloped state institutions. they aren't really failed states, but more so "unfinished" states

similar examples include belize, papua new guinea (abandoned by australia), East Timor, vanuatu, djibouti, maldives etc. some marxist, some british, portuguese, french, etc

in many of these countries you really can do what you want. belize is not much more than a forestry plantation with 19th century english corporate law and a few bars in the capital ("Belize City").

Laos is a pretty odd state. I looked up their official news site once expecting to find North Korea style propaganda, but it was instead surprisingly straightforward about a lot of day to day problems. I also had some contact many years ago with their one Linux/Free Software enthusiast. My impression is that it's a fairly weak state, and the main reason the communists are technically still in charge is that nobody really wants the job of ruling Laos particularly much.

Is there anything that capitalism did that is different from what it preaches?

Why though? The essence of communism is banditism