18-34? Yeah I am pretty financially fortunate and literate and I did not start saving for retirement until 24
And only pretty recently did my budget really have room and a salary big enough that 10% was a chunk of change....
But yeah 1/3 of their age range here generally will not be saving for retirement because they are likely students and/or minimum wage workers. If you make $12/hr at 21 it's basically inconsequential if you are putting $800 a year away toward retirement.
I just punched it into a calculator. $100 a month, 6% interest and 3% inflation, for 40 years nets you $60k of buying power at retirement.