I disagree a little with the 5 years part as I can see a small chance of “a collapse” happening within that time, but as for the 30 years part it seems possible too.

As they have to steal ever more from their own populations and can steal less from the Global South they will become weaker and fractured, and if, for example, this happens in some parts before others it can lead to fascism in some countries in Europe which might see their neighbors in better shape as enemies, potentially leading to western infighting and an acceleration of their own collapse.

Hopefully such a scenario the conflicts stay internal instead of going global and they only weaken themselves while the rest of the world prosper. And in such a scenario we could even see Global Sout countries with enough power to massively influence western countries perhaps even leading to imperialism against them as the Global South is unlikely to go communist so fast.

Other scenarios might be more plausible though…