Exactly.  The only "solution" is absolute centralized checkpoints which prevent reorgs prior to the checkpoint.   PoS proponents often bring up that Bitcoin uses checkpoints however they are not necessary to enforce the security of the blockchain.  Case in point the oldest checkpoint is more than 5 months old, and a 5 month reorg would destroy Bitcoin.  Checkpoints are used by Bitcoin to prevent an attacker for wasting the resources of bootstrapping nodes as a DOS attack by feeding them spoofed chains.  There is no requirement that they be centralized.  Different clients could use different checkpoints at different block heights and it would work just as well.