I've been meaning to update this thread for a while.
I'm still mining, and it is still profitable to do so, but it's pretty hard to determine exactly how profitable, for a few reasons.
First, when I started mining , ETH was at something like $3 or $400 (AUD) whereas now it's about $1200, so while I was making about $50 a month early on, it's closer to $200 a month now. It depends how you calculate your profit - on immediate or future value? If you believe in a particular crypto, or the market in general, mining at a loss now might eventually become profitable if you HODL.
So the price fluctuations make it difficult, but another issue is that I don't really care to calculate in depth anymore. A few hundred worth a month is nice, and gives you a steady stream to consolidate or take new positions, but it's barely significant in comparison to trading gains. When your portfolio can increase by $1000 in a day, it's hard to dedicate much time towards acquiring $200 a month.
Thankfully, I don't need to dedicate any time to it. it just runs, and periodically gives me a bit more funds to sink into crypto, which has now taken the place of DCA. I haven't put any money into crypto for months, and have even withdrawn my entire principal (plus a bit more) while my balance continues ticking upwards.
It won't last forever though - the amount of ETH I could mine was steadily decreasing, which is why I switched to ETC a few weeks ago. It was just lucky that ETC happened to pump soon after, and if that trend continues, mining it will be profitable for a long time to come. And when it's not, I can switch again to lower difficulty coins, or turn the miner off and use the powerful PC I've built for what it's meant for - gaming and VR.