Putting your coins into someone else's custody means you also lose your most direct input to their governance

I read the description of one ETF just now, and to quote from it:

Pursuant to the terms of the Trust Agreement, the Trust has disclaimed ownership in any such IR [ed: fork or airdrop] Assets and/or Incidental Rights to make clear that such assets are not and shall never be considered assets of the Trust and will not be taken into account for purposes of determining the Trust’s NAV or NAV per Share.

Not only would you as participant in this scheme NOT own the real underlying assets.

It seems you would lose a meaningful power of governance in influencing the development direction of the assets.

Owning the underlying asset directly (i.e. through self-custody) would enable you to dispose of any forks or airdrops as you see fit:

• you could decide to sell one side of a split and re-invest that in the other
• you could decide to keep both as a valuable part of your portfolio and see how they develop, postponing future buy/sell decisions
• you could even decide to get rid of both sides of a split and get out the full market value of both at that time

See how this differs from the position you're in with a custodian that owns assets but disowns potential coin splits?

To the extent that people delegate their wealth to ETFs and such, they weaken their own power to make important governance decision and timeously¹ determine what is valuable and what is not.

Food for thought.

^{1 - yes, you can still withdraw from a custodial scheme and repurchase the underlying assets, but once a split has happened it'll cost you even more to acquire the full range.}