You mean legally? Because technically in GoG you can.
"Your GOG account and GOG content are personal to you and cannot be shared with, sold, gifted or transferred to anyone else."
Now, moving a steam account into a trust might be a breach, if they care. Even using a trust to buy a game might also be a violation of some form, perhaps, buried in the toc.
But the trust itself is a legal entity and it can own things. Just because the people behind the trust changes doesn't mean it was a transfer on the public side of the trust.
> Now, moving a steam account into a trust might be a breach
Morever, it can't happen. Accounts are non-transferrable.
> Even using a trust to buy a game might also be a violation of some form, perhaps, buried in the toc.
Right at the top, actually. GOG, not Steam: "This license is for your personal use."
It may not be legal, as I said.
So you CAN pass your collection over to your heirs on an hard disk.
Whether this is legal it’s a different matter.
GOG is very clear on this: you CANNOT provide the installers to anybody, those are for yourself only. It is easier, for sure.
It's still a terrible situation that should be solved legally.