Why need antes when we have blinds

[grapabo]

Is the OP asking for a comparison of an opening pot of 4500 chips made up of, say, 1500 from the small blind and 3000 from the big blind, versus an opening pot of 4500 chips made up of 1000 from the small blind, 2000 from the big blind, and 1500 combined from ten players contributing 150 each? (Forgive the slightly off numbers for the sake of simplicity.)

I guess in theory, the bigger pot could be made up of bigger blinds alone, but I think the ante is used to build the pot because it induces action in two ways - it makes for a bigger pot, and i forces a contribution every hand, rather than just when it's your turn to post the blinds.