Preseason: Ranked Queues

Can someone please explain to me what the deal is with ranked queues this preseason? Last preseason, our ranks went away, we had placement matches, we got placed, and then any progress we made was taken into account when the new season started and we did our real placements. What's the deal now? We still have our end of season rank and LP but is there a point to playing ranked right now? I don't want to put the effort into tryharding with my mains if there is no benefit.