The other advantage to that would be that if you know you'll be participating in enough events to attend Worlds that you can plan for it in advance, rather than "hoping" that you get a bid. I think you'd see more teams attend Worlds.
And if you want to make paid bids more prestigious, give paid bid winners a bye of some kind. Maybe have three rounds of competition and paid bid winners get a bye into round two - or something like that. The only rule would be that EP's would have to agree to a uniform standard for giving out bids.
They are already doing the 2nd part... Paid and partial paid bids skip prelims and go to semi finals