A lot of companies offer retirement plans where a % of income is invested monthly, a la dollar cost averaging (e.g. 401k plans). It's really easy to set up and let ride on autopilot.
Fast forward to age 50, when you're making 200K (this is 28 years from now, so inflation and pay raises bump you very high), you're putting in the same %, but that equates to $18K/year.
So even with dollar cost averaging, the majority of your money is invested in a small, 10 year time window when you are at peak earnings.
At age 22, you make 25k and get 0% matching, and can afford 0 to put into your still-hypothetical retirement fund.
At age 50, if you're the median person, you make 50k. And you need that money to put your kid through college.