Layers and transaction fees in the future


What's the general thought on how transaction fees will scale as time goes on? As lightning picks up, it feels like most smaller transactions will use that layer due to higher volume and lower fees.

Do you think there will be a movement towards larger values being moved on the lightning network as usage and trust grows? If that happens is there a danger the layer one security gradually decreases because there is less traffic being transacted on it and less incentive for the miners?

Any links to discussions on this would be appreciated, I'd like to fill my knowledge gap!