Burning takes $RUNE out of circulation and stops there.
Protocol-Owned Liquidity takes it out of circulation too, and keeps it working.
Every block, 20% of THORChain's system income goes into the pool that earned the most fees for its depth over the last 3 days. Arbs pair the RUNE with the token on the other side, so the protocol ends up holding RUNE and $ZEC, $TRX or whatever else swappers want most.
That position does three things a burned token can't.
-It earns swap fees.
-It deepens the pool, so swaps get better prices.
-And it buys the dip: when $RUNE drops against the paired token, the position trades part of that token for more RUNE, automatically.