Byzantium is a really good example for this kind of thing. Its existence was due to a broader breakdown of the Roman imperial structure, and the history of its existence is the narrative of extended decline. Asking when did the Byzantium Empire pass the point of no return can get a lot of answers. Which one is taken as the primary depends heavily on the criteria for what collapse means. Is the complete eradication of the state as an existing quality, then 1453. But the Byzantine empire of even the 11-12th century would look like it had fallen apart when compared to the 5th-8th period, let alone from the 13th century onwards. One could argue the plague of Justinian was a point of collapse, as after that the Byzantium were controlling losses rather than building territory. 1453 was not even the first time Constantinople was sacked as it also occurred in 1204 and saw the Byzantium elite at the time become refugees. Byzantium persisted for another 249 years. To put that into perspective the USA as a political entity is as of today 248 years old.

There is no real 'point' of collapse that is experienced in real time. It's dated retroactively most often, but retroactive dating doesn’t really take into account the individual points of societal breakdown. And hegemonic institutions take a long time to fully disintegrate. Post-sack Byzantium persisted for a long time. And throughout the latter few centuries of its 1000 year existence was going from crisis to crisis. Then the broader implication of Byzantium being in essence the continuation of the Roman state, if reduced in size, then even the Roman empires collapse has a timeframe going over 1000 years of history. While the contexts of the modern world is starkly different to that of late antiquity and the entire medieval period (with a common date of the start of the early modern period being 1453 due to Byzantium’s final end) true collapse on state level can take a long time. But people, as in individuals, are not political states. Individually the Byzantium empire collapsed multiple times. And depending on when one was born, becoming a Byzantine was itself living though a Roman collapse.

All this to say trying to predict this stuff is impossible. What matters often to a question like this is, “from which perspective?”. Because depending on the perspective there is a real possibility that somewhere like the US has never been in the position to collapse, because they come from a historically disenfranchised minority. Other’s might say that far from collapsing the USA is still developing, women for example have greater rights now than in 1950, even with everything going on right now. In the same sense a Byzantium elite who became a refugee in 1204 would say that’s when it died, as a contemporary  of the time wrote (translated by Micheal Angold in 1977),

“The peasants and common riff-raff jeered at those of us from Byzantium and were thick-headed enough to call our miserable poverty and nakedness equality...Many were only too happy to accept this outrage, saying "Blessed be the Lord that we have grown rich", and buying up for next to nothing the property that their fellow-countrymen were forced to offer for sale, for they had not yet had much to do with the beef-eating Latins and they did not know that they served a wine as pure and unmixed as unadulterated bile, nor that they would treat the Byzantines with utter contempt.”

For those leading the Latin Empire though, this was a founding moment for a new entity governing over the following 61 years. Something of a generation in other words.