Your argument about the Sri Lankan and the Congolese is actually aligned with the degrowth movement. One of their key points is that economies of the global north should consume less so that the global south (e.g Sri Lanka and Congo) can continue to grow to support a baseline standard of living for their citizens. In other words, rebalancing the global "budget" - assuming the world actually cares to lift this people out of poverty.
What we should consume less of on the absolute scale is non-renewable and non-recyclable resources, like oil, or land (agricultural and otherwise), or hard-to-recycle plastics. Consuming more electricity is fine if we produce it from sunlight or even uranium and the current stockpile of "nuclear waste". Consuming more steel and aluminum is fine since they are about 100% recyclable. Consuming more wood is also relatively fine, as long as we grow even more trees (and we do).
Any proponent of de-growth should spend a few years in countries like Sri Lanka preferably in a village without access to the last 100 years of medical tech, without access to the internet, without modern water treatment.
It feels okay to advocate for degrowth because we notoriously underestimate how much standard of living increases as a result of growth.