And this has not just been due to their own direct actions, but the failure of self-custody products are well.
This is misleading.
Most of the money lose throug self custody are due to the direct action, or inaction, of the person. Only a few of them have been a result of the self custody product, like the ColdCard case.
I think the very sentence you quoted there made the point clear. I assume the majority of losses due to self-custody are from and individual's theft or mistake. I didn't imply that products are the main culprit.
I wish I was making this up, but just yesterday, my dad called me, and he was with my younger sister. They complained about how $500 was withdrawn from my sister's account as far back as March of this year, and she had no idea that kind of transaction took place. She wouldn't have known this if she had not requested the statement of account. The bank is claiming she made the transaction and has refused to show further proof.
Now there is going to be a lot of back and forth with the bank if that money is to be recovered.
Now imagine this was a large sum.
If it was a large sum then they wouldn't try it because they know it would lead to costly litigation.
Of course solving this problem would involve the legislation championed by a certain crypto boogieman ("boogiewoman"?) named Elizabeth Warren, who gave individual consumers power to fight back against small-dollar infractions like this. For a while US consumers had real recourse when banks pulled stuff like that, but Trump and the Republicans rolled it all back and if you get a mystery fee of $30 on your next bill there's not a thing you can do about it.
(Of course in the absolutely unregulated world of crypto, you have even less recourse).
My point is, don't make it seem like once your funds are insured, you have nothing to worry about.
Insurance isn't a panacea, but it reduces stress by quite a bit.