Look at the data of growth that different blocksizes would mean, look at the latency, the whole thing, it's just a mess. Bitmain wants 8MB by august 2018... insane.
Again it's not only growth of data but latency and other issues, the percentage of growth depending on the blocksize varies heavily.
https://www.youtube.com/watch?v=iFJ2MZ3KciQ&t=49m
I recommend to watch this full video but this is a good section explaining it.
Bicoi is a digital currency many people said that Bitcoin is like an asset more than a currency nowadays because if you hold a single one of it way back in time and wanted to sell it in today's value you will really getting a big profit. Bitcoin is the digital currency use full to the online purchases and transfer the money for the developers