I had a look at hivestats.io and most people make about 5 - 8% APR from curating

It's not directly comparable because HIVE/HP has potential for appreciation. Within the past year it went up as much as 2000%.

The yield on HP makes sense to compare if you are considering holding HIVE instead (tradeoff between yield/curation/voting for HP vs liquidity for HIVE), but doesn't make much sense to compare it to a stablecoin.