Nobody's counting government benefits. The US also has a similar policy called Social Security and Medicare (for healthcare.) The average lifetime payout for someone retired today is about 1 million. For someone retiring in 2060, double that.
By your math, the US millionaire couple about to retire is actually 'worth' 3 million.
Also, your numbers are misleading. The average lifetime payout numbers include Medicare benefits in addition to Social Security. You should also use estimated present-day values instead of lifetime payouts if you want to compare benefits to savings.
Median full-time income in the US in about $55k. A quick estimate for Social Security payments for someone retiring today at the nominal age with that income is $1580/month. That becomes ~$38k/year for a couple, which is ~$750k using the 5% rule. Median household net worth, including primary residence, is ~$250k at retirement age.
My estimate was based on a median income of ~$40k and pensions that pay ~60% of income. That would become almost $1M for a couple using the 5% rule, in addition to ~$200k household net worth at retirement age.
By these very rough estimates, the median recent retiree is worth 9 years' income in the US and 15 years' income in Finland. That supports the idea that there is a shortage of millionaires in the US.
Yes, that's the problem your parent comment is pointing out.
You're not trying to count them either. The value of a pension isn't the payouts it provides. It's what an identical financial structure would cost. A pension that pays out $1 million over 15 years is worth less than $1 million.
You appear to be correct on the original point that US social security payments are pretty comparable to Finnish pension payments. As of March this year, the average Finnish payment was 1784 euros and the average American payment was 1537 dollars.
By your math, the US millionaire couple about to retire is actually 'worth' 3 million.