In order for Bitcoin transaction fees to become lucrative enough to encourage mining, Bitcoins value is going to have to rise substantially. Luckily, certain traits are built right in to Bitcoin to ensure just that.
People were mining when Bitcoins were worth $1. A lucrative block reward is not necessary.
Times change bro. I don't think there would be anyone who's willing to mine btc at sub 100 usd. If that's the case then miners would most likely shift to mining eth or other alts that definitely would be more profitable than mining bitcoin. Profit expectations were raised way up after 2017.