IMO, you’ll never get a social retirement system funded to pay for a median household replacement income in retirement. The average social security payout for recipients is around $1500/mo. The max is around $3100/mo. Median household income in my state is ~$6800/mo. You would need to double social security to pay every 2 average recipient household 88% of the median income. You would need to quadruple it to pay a single recipient 88% of median.

Plus, not everyone wants to work to 67 (full retirement age for SS for most workers today). Then, not everyone wants to drop their spending down to that of a median income household.

Combine those factors and social retirement systems aren’t going to be the solution to stop people from saving and investing privately to supplement.

I can’t see social retirement ever being funded to the level of a middle-class retirement; I think it’s a useful safety net to ensure people who worked their whole lives but didn’t save privately don’t starve, but dramatically expanding it is mathematically difficult to fund.