Are you equating receipts with tax level? Tax is a rate applied to an income or wealth amount. Note that GDP includes government spending, which is not subject to tax but is based in part on debt.
If you are in favor of more taxes nominal vs effective rates is not a can of worms you want to open. Effective tax rate was lower in the past even if the nominal was higher. SALT was amounted to basically nothing back then whereas they are far more now.
sure but that sword cuts both ways. it is well documented pretty much nobody actually paid top nominal rates in the 50s because there were so many loopholes
Why choose that metric rather than income, corporate, capital gains, etc. tax rates? Seems like it could obfuscate who bears the burden of those taxes.