I don't. I think it's easy to agree with though which is why I forced myself to think about it.
As is, self-custody is:
  1. non-trivial
  2. predicted to be increasingly unsustainable economically for all but the largest UTXOs
The only way to determine this was through a survey. I want to emphasize that I strongly disagree with the assertion that, simply because there is no current interest in self-custody, we can ignore the need for scaling. I was simply pointing out the fact that people aren't keen on self-custody.
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I believe Spiral funded such a survey last year and the author's of Resistance Money have been discussing a more recent one. I'll try to dig them up soon and see if there's an attempt to measure this.
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