I'm confident that if the network doesn't double in hash once it matures every year aka grow in accordance to Moore's law, then the network will become insecure and miners will abandon it for other, more miner friendly, PoW currencies.
How do you figure? the network is supposedly already more powerful than the world's top 500 supercomputers combined. If it shrinks a little bit,
it's still plenty secure.
What do you mean by "miner friendly"
What I mean by miner friendly is a cryptocurrency that has more than one revenue source for miners, or an inflationary PoW cryptocurrency. A cryptocurrency with a fixed amount of bitcoins will eventually solely rely on tx fee's to support mining growth. An inflationary currency will rely on tx fee's as well as block reward. The only question is the amount of inflation that is required to balance mining profits and price stability.