As you point out, it’s better to observe history and the boom/bust cycles to extrapolate that this will not last. I’d wager the next bust will be even bigger than anything in our lifetime, but would be a happy to be wrong.
* it is impossible to predict the (economic) future if it is your job
* any layman can predict the future through simple extrapolation of GDP variation around the long term trend
So why are economists so much worse than the layman?
Part of it might be due to "insider" (not in the illegal sense) knowledge (aka "expert" knowledge) vs "outside" knowledge.
In other words, economists apply a great deal of thought, knowledge and expertise in making their calculations. The problem is that the future is inherently unpredictable, and in the end, all their effort is spent on elaborating what is, in the final analysis, just a story.
For outsiders, they basically admit that they don't know very much, and just resort to naive base rate analysis.
Yet it often turns out that naive forecasting is actually better than elaborate forecasting, because you're not kidding yourself that you know something when you don't.
“What gets us into trouble is not what we don't know. It's what we know for sure that just ain't so.” -- Mark Twain