Something to bear in mind, perhaps who owns our shares may be as important as what they own.
We are giving immense voting power to the big ETF holders (Blackrock, Vanguard) and perhaps we shouldn’t just be considering their costs and tracking error but their voting record. Maybe in future we will look at our custodians voting record when deciding whether we buy an iShares or Vanguard ETF in the same way we look at an MP’s for voting.