It shifts a lot its a debatable thing especially as new ASICS come out that affect older ASICS and thats what really drives difficulty up and if bch fails a lot would move back to btc
With current market conditions I don't think any token mining will give profit. Crypto is the future, it's growing Baby juts needs to go through some more hiccup.
time will certainly reveal a lot for all we know BTC is not the holy grail may be some other crypto will take its place, ETH will have to solve its scalability or risk been replaced by other platforms. the field is still fresh