The naive comparison above
Your wording tran

That said, yes, the comparison between gold ETF and BTC ETF is not very meaningful
if by doing that you want to compare investment flow into gold and BTC.
You have to compare the role of ETF investment within the whole investment for both of those assets.
Then you see that
structurally gold ETF investment is much less relevant than BTC ETF investment.
Think e.g. of Central Banks.
While CB investment in BTC is still zero, CB gold buying represent a major investment flow for gold, bigger than ETF.
While ETF is going to become the major investment vehicle for BTC, ETF was never a major investment vehicle for gold.
Think of the two major gold buyers worldwide, India and China.
ETF investment is basically irrelevant there.