So if your voting value is 20 POB, and you upvote 10 posts a day. That means you'll earn 100 POB daily as curation rewards

Really? Is that how it works. I thought 50% goes to the author and 50% goes to curators to share.

Anyway, staking gives you skin in the game, and stake on the platform/blockchain. This is ownership. We all need to own things. This is something that has been taken a way from us by the government. People dont own things anymore. They only have license to things and it can be taken away whenever the government sees fit.