the idea of difficulty to prevent "inflation". For example if total hashrate doubled, "difficulty" will also double to neutralize it. hashrate/diff = const (ideally).

It means that 71.5mh/s will be equivalent to 400/100*21.5=28.6mh/s. But you need to take into account prices of coins/BTC. They also tends to equalize. But you know that ideal equalizing is death

since cryptocurrency wolrd is still alive, some coins will be more profitable than others.

Ahh alright! So in my instance, not taking into account prices of coins/btc and just number of coins, I would be better with the Lyra2v2 algo then is what I'm getting from this. It's because Verge has multiple algorithms to keep it as decentralized as possible, even the mining process. So there's scrypt, x17, myr-gr, lyra2v2 and blake2s. That's why I'm only concerned with number of coins as the price of coins is the same across algos.