many ways to get bitcoin without buying it with FIAT,
For example, in this forum there is a bounty where there are various campaigns such as social media, articles, signatures and much more.
You can exchange your income from the bounty with bitcoin, my friend
besides that you can also trade daily, weekly, so your usual profits buy bitcoins or you trade in BTC pairs
For you to trade it requires you have money that you will first invest, which eliminates his whole idea of earning Bitcoin without having to buy it with FIAT.
And of course I do know that earning bitcoin these days without fiat is a very difficult thing to do, it isn’t like in the old days when bitcoin was being giving out for free, and there are lots of ways to get it online just like faucets (I knew a lot of faucets back then that were really paying well, and one of them I knew back then was even paying up to 700 satoshi every fives minutes, while others were paying 50, 100, or so.). Well, I think his best bet would be through campaigns.