The both are decentralized, and the both have limited supplies, the list goes on...
First of all, gold is not decentralized and it is not the same as Bitcoin - gold is controlled by central banks and governments. And if you see that gold is not really limited, it can still be mined, whereas Bitcoin's supply is limited to 21 million and you can't mine it anymore when the supply is exhausted. And when discussing which one is more worth it to invest in? I prefer Bitcoin, you can say various advantages of investing in gold, but I prefer Bitcoin to invest in right now, it has more potential and you can invest easily without needing a certificate like gold.
Potential to get broke
Last coin (if it will be mined) will be mined long time after we are all dead, so for us, today, it doesn't really matter.
Long time after our death developers can decide fees are not enough to sustain mining operation and will switch to PoS like Ethereum did.