I wouldn’t go so far as to say “can’t afford”. It depends on who runs and how they run the plans, frankly. All too often, graft, greed, corruption and misuse of these plans are what causes them to fail.
Ultimately the operators of these plan fall back on the public as the guarantor of the commitment and throw caution to the wind and bathe in the excesses made affordable in their ‘management’.
In truth, the managers of the plans in question should be subject to the same travails as the elite of 1799 France.
What it turned into:
1. massive compensation equal to or greater than they made while actually working
2. qualified to earn the above after only a few years of work
3. getting the above, welfare and 2 other+ pensions from other jobs they also only worked at a few years.
4. receiving all the above for longer than the total time they ever worked because of lengthening life spans.
I am sorry, but that just is not a sustainable idea.
Call me mean spirited if you want, I call myself a realist.