Bitcoin and other proof-of-work (no actual useful work being done here either, opportunity wasted!) based crypto-currencies increase the proof-of-work algorithms complexity factor as a means of controlling the rate. Bitcoin cannot scale up without using an ever increasing literal waste of electricity. Want a better system? make a new crypto-currency trust basis... (proof of stake, etc.)
https://en.bitcoin.it/wiki/Proof_of_work
https://changelly.com/blog/proof-of-work/#Proof-of-Work-Draw...