Revenue did indeed decline from 2000 to 2010, but the trend begins to reverse quite immediately after 2010. On page 15 of the 2023 IRS Data Book [0], total reported revenues were:
1980: 519,375,273,000 (in 1980 dollars)
1990: 1,056,365,652,000 (in 1990 dollars)
2000: 2,096,916,925,000 (in 2000 dollars)
2010: 2,345,055,978,000 (in 2010 dollars)
2020: 3,493,067,956,000 (in 2020 dollars)
Adjusted to 2010 dollars using a calculator from the Federal Reserve Bank of Minneapolis [1] for sake of comparison:
1980: 1,374,294,904,976 (in 2010 dollars)
1990: 1,762,975,620,417 (in 2010 dollars)
2000: 2,655,315,429,720 (in 2010 dollars)
2010: 2,345,055,978,000 (in 2010 dollars)
2020: 4,145,927,700,959 (in 2010 dollars)
Using the population figures from the census data you provided, this works out to a per capita revenue of:
1980: $6,066.30 (in 2010 dollars)
1990: $7,088.48 (in 2010 dollars)
2000: $9,435.35 (in 2010 dollars)
2010: $7,595.43 (in 2010 dollars)
2020: $12,508.48 (in 2010 dollars)
Note that this trend continues through 2021, 2022, and 2023.
I notice that some of the decreases and increases in revenue seem to correlate with periods of relative economic prosperity (e.g. the height of the dotcom boom around the year 2000) and periods of relative privation (e.g. the economy was still recovering from the Great Recession in 2010). I don't have any insight into whether these macro events have a more substantial impact on revenue collection in comparison to any changes in tax policy that might have occurred during these periods, but it doesn't seem like a coincidence.
[0] - https://www.irs.gov/pub/irs-pdf/p55b.pdf
[1] - https://www.minneapolisfed.org/about-us/monetary-policy/infl...