The main problem seems to be that miner income from the block reward will eventually go to zero due to the halving cycle. An interesting question is what impact increasing the blocksize along with hardware improvements would have on the long term security of Bitcoin. Couldn't the decrease in miner income from the block reward be off-set by an increase in miner income from transaction fees?

Where can listen(or read) Claire Bao's speak(paper) about "Transaction Fee Dynamics and Undercutting"; please?