At the risk of sounding condecending, retension package = to retain staff. If you're not leaving then you don't need to be retained. This retension lock in is designed specifically to persuade those that want to leave not to. That said, you're welcome to the money those threatening to leave are organising for you.
You're absolutely 100% entitled to stay without any recrimination from anybody, least me. I'm not judging you in the least for it. Don't hold it against me though for wanting to leave though. As stated previously in this thread I'm not leaving for money but for a better life for my family.
Many others are leaving for more money. Again, it's a choice we all make for ourselves and for whatever reason they leave it's not to be judged by others.
Do not however be told by the company that you're earning a market related salary because you're not.