Looking at how the PoS was implemented for luna is kinda scary and shows some of the issues I have with PoS generally.
They had a whitelist/blacklist system for validators, which seems to have been manipulated to keep validators to "friendly" ones, and then in the midst of the crash they locked down staking and the ability to create validators at all, leading to 0.003% of the outstanding luna (classic) being the only ones able to perform governance and the 100 or so remaining kwon-friendly validators being the only ones able to run any future validator nodes.
Just being able to fire up a mining node whenever you like is vastly superior.