are people still mining it and what are the requirements to do that, at least to recover my past ignorance?
Yes. Without miners, Bitcoin network would die since no one create block and no TX can get confirmed. As for requierment, check whether you have access to electricity with price rate about $0.06/kWh or lower. Otherwise, ROI could take very long time or even never happen depending on hashrate growth and Bitcoin price in the future.
Then my friend said, there is still an alternative to do it, that is by mining altcoins that have a low difficulty level, then after you get the block reward, you can sell it & buy Bitcoin.
It's not that simple. Low difficulty usually means that altcoin have low price or mining reward, where you usually mine at loss. And if that altcoin can be mined by ASIC, it's probably dominated by big scale mining business (or "hegemonized by rich people" according to your word).