However, it is anticipated that the 2020s will conclude well below the total inflation levels witnessed in the 1970s and 1980s.
Based on what exactly? And who is anticipating this?
lol the same people who told us that the economy was doing great this whole time
Have you considered it's only 2% inflation in this year of our lord 2024? 
I have no raise and I must scream.
The 1960s isn't including here, and yet that's when things started to go off the rails, culminating with the end of the gold standard. The core problem underneath all of this is the neverending search for infinite growth in a finite world. We almost hit a few brick walls but managed to innovate our way around them, each time into a deeper hole we can't climb out of. I'm sure we can keep that up...
Amusingly, one of the primary factors driving the decline during the 60s was the Vietnam war, and today it's the proxy war in Ukraine.
I'd suggest reading Michael Hudson's Superimperialism for some background on why the US went off the gold standard. To succinctly summarize, it's because the US had dug itself into a massive balance of payments problem in the post-war period, primarily due to the imperialist wars in Korea and Vietnam, and had no way out beyond simply telling the rest of the world that it wouldn't be bothering to balance its payments anymore.
Dropping the gold standard was a means to an end, not an end unto itself. It also wasn't done overnight in 1972, there was more than a decade of soft-dropping leading up to the final event.
I always cringe a little internally when I see someone pointing at the dropping of the gold standard as The Thing[TM] which has defined the neoliberal era, as in my experience it's some sovereign citizen type dreaming up some anarcho-capitalist world in which gold (coin) and lead (bullets) are the only two payment instruments worth anything and there is no such thing as society anymore.
News from within the empire - From a leftist perspective