It's not for GPU coins, but some altcoins are pop in and out of profitability on CPUs, if you balance it in realtime you can make money. (I have an employee doing this as a learning project)
But if making a lot of money is your goal then you're better do it it trading, no I'm not going to elaborate
I remember seeing stats that something like 90% of the traders lose money trading stocks. I'm sure it's the same in crypto, though it's compensated by the nearly constant growth. I doubt though that many traders beat the simple buy-and-hold strategy.
But if making a lot of money is your goal then you're better do it it trading, no I'm not going to elaborate