You're not including the defined contribution retirement plans, which are a vehicle for investment.
N.B. I believe 'pension' ≡ 'defined benefit' is an American English thing, which may the source of the confusion. I, my employer, and my provider refer to my private, defined-contribution plan as a pension.
You’re also forgetting all the people without pensions, but with IRAs and/or 401ks. And then the many more with brokerage accounts. And young people seem to have jumped headlong into Robinhood.
However less than 2.3% of hourly workers (not total workers, but hourly workers) make minimum wage, yet those that claim a good stock market doesn’t benefit most people would argue fiercely over minimum wage which affects only a tiny fraction of workers. So we should be applauding something that benefits “only” 13% of the workforce (though that 13% number with pensions is misleadingly low as pointed out by other comments.)
N.B. I believe 'pension' ≡ 'defined benefit' is an American English thing, which may the source of the confusion. I, my employer, and my provider refer to my private, defined-contribution plan as a pension.