@grillchen truely. Thats why multiple sources of retirement stuff. Switzerland does this quite well. They have a mandatory state-like thingie, employer-benefits and you can also put stuff in special retirement stuff.
Mostly gets tied up my insurances that will gurantee you a certain something will be paid.
But yeah for stock based pensions alone... Its shit.
A reason why we really need more Betriebsrente in germany. But corpos don't like that to be mandatory since it can really squeeze you for cash in a smaller firm (or even big ones can fail on it). Also I guess they would succesfully complain to the government it never happens