There are a few points that could be made. The primary point is that even though they might score low on some metric, the people of Bhutan are pretty much all well-off and happy. The king decreed democracy not long ago. It's a kind of "existence proof" that people can pretty much be alright.
Consider a couple of other stats from that site:
> the proportion of population with access to electricity in 2020 was 100%.
Sure, but that’s the answer to “can poor people more or less be alright “. Which while interesting is orthogonal to the question of “can a society exist with no poor people”.
Fair enough, but I feel that, at that point, we're getting into semantic weeds over the definition of "poor", eh?
For concreteness, I'll say that I would define "poor" as not having the capability to satisfy the lower tiers of Maslow's hierarchy. ( https://en.wikipedia.org/wiki/Maslow%27s_hierarchy_of_needs ) By that standard Bhutan isn't poor despite being technically a Third World nation.
I think it’s axiomatically true that if you change definitions at will then anything can mean anything. I don’t think that’s useful for enhancing understanding.
Consider a couple of other stats from that site:
> the proportion of population with access to electricity in 2020 was 100%.
and a 2.5% unemployment rate.