I’ll just add that from 2016-2020, Trump perpetuated a zero interest rate policy despite the economy booming.

Macroeconomics 101 says this will cause inflation on a few year delay, which is what happened, and Biden was also blamed for that.

ZIRP (also, Quantitative Easing or QE) was the policy since 2008. Rates actually rose in the first Trump admin [1] so this isn't quite as causative as you suggest. Other things did happen that contributed to the inflation shock of 2020. This goes back to the Obama admin too, specifically:

1. After the OPEC oil shock of 1973, the US banned crude oil exports (in 1974 I believe);

2. In the early 2010s, hydraulic fracturing ("fracking") was invented, which created the US oil boom in the Permian Basin (from west Texas up to the Dakotas). Almost all oil wells in the last 10-15 years have been fracked. This was a massive capex outlay by oil companies at the time. This is important;

3. Obama, facing a hostile Congress in 2015, wanted solar and wind subsidies so he made a deal with Congress that included lifting the 1974 crude oil export ban. Oil production quickly went up and ever since we've been exporting ~3Mbpd of crude oil, which is essentially excess demand, and this is how the US became the largest single oil producer in the world;

4. OPEC but really Saudi Arabia in particular crashed the oil market in 2015-2016. There are two competing theories on why they did this. A lot of people think it was to kill the frackers. I don't think this makes sense. It was years after fracking came about. I think it was to punisht he US for becoming a crude oil exporter. And it worked. Roughly half of oil producers and services companies went bust [2];

5. When oil prices are low, producers will generally suspend production until prices increase because they're selling at a loss. They'll layoff staff and come back when prices improve. So this is self-correcting. But oil companies had to keep selling because of their massive debt;

6. Because of (5), oil inventories exploded and when Trump took office in 2017, oil experts believed that oil prices would remain low because of persistently high crue oil inventories [3];

7. Trump pulled out from the JCPOA in 2018. To counter expected Iranian sanctions, Trump got OPEC to increase production [4];

8. In October 2018, Saudi agents, allegedly on the orders from MBS, killed Saudi citizen and US permanent resident Jamal Khashoggi in a Saudi embassy in Istanbul. I actually believe this is relevant to what happened subsequently; and

9. In November 2018, Trump granted 8 waivers to Iranian oil exporters to continue exporting [5]. This crashed the oil markets [6] and basically screwed over OPEC. But I think MBS had to eat it because of the Khashoggi fallout.

So come 2020, it is my belief that when Donald "Art of the Deal" Trump got MBS to cut oil production and then MBS later refused to increase production (to both Trump and Biden), it was payback for 2018.

So I don't think there's any causation between ZIRP and the inflation shock. It was a combination of two things: the oil price shock and the pandemic became the perfect environment for companies to raise prices, something many believed they'd get punished for prior. This is the era when dynamic pricing really took off.

[1]: https://www.reuters.com/business/energy/us-oil-producers-pac...

[2]: https://fred.stlouisfed.org/series/FEDFUNDS

[3]: https://www.eia.gov/todayinenergy/detail.php?id=29532

[4]: https://www.cnbc.com/2018/06/22/opec-ministers-strike-deal-o...

[5]: https://www.cnbc.com/2018/11/02/trump-will-grant-8-waivers-t...

[6]: https://www.cbsnews.com/detroit/news/the-great-oil-crash-of-...