ROFL. If the purpose of Bitcoin was, "to teach people to be more responsible", it would have about 47 users worldwide

.
And self-custodied funds can be sized and taken as well, so I'm not sure what the point was there.
I feel it is to teach people to hold their funds instead of trusting banks and financial institutions. And there are more than 47 users who are responsible hodlers of their own Bitcoin... you know that right? lol
Yes, but only 47 of them use Bitcoin as a means of teaching themselves something (probably less than that, actually).
The other 99.999% of Bitcoin holders hold it to... make a profit.
if self-custody is done correctly it cannot be seized. Maybe it can be given up but not seized without the owner allowing it.
LOL, "given up" versus "seized". Okay.

The words don't matter: a government can get your Bitcoin if they want your Bitcoin and they know where to find you, just like they can get your car, your house, your collection of rare baseball cards, or whatever.
If you want to make a case that Bitcoin is easier to hide from the cops if they are after you, then maybe that could be, but most people don't live their lives afraid of the police taking their money. If that's what Bitcoin was really used for exclusively, there would be 99% fewer Bitcoin holders...
And if you are saying that Bitcoin's primary purpose is to hide money from the police, then... you are agreeing with Bitcoin's most consistent naysayers...