Comparing leverage on ETF to be able to borrow billions of dollars at 0% with no margin call is like comparing an elephant to a mosquito.
What is exactly the advantage for the investor? These billions are only invested in BTC.
The fact that there is no margin call, no risk of liquidation (or if you prefer a risk so low that is extremely unlikely, especially compared to a leveraged position in an ETF, that can be margin called).