Are people really unaware that encryption doesn't limit the information they send to only ever be viewed by the intended recipient? That's not how and never has been how encryption works, it's not a mission impossible letter that self destructs.

The point of E2E encryption is that you trust a recipient and don't trust the medium data is sent through to the recipient. Once the recipient has the information, how well you assessed your trust in the recipient is what matters regarding the security of the information you sent. Nothing has ever prevented the recipient from breaking that trust and sharing information sent to them.

There are of course ways of reducing access to the recipient of the information through a specific technology (view once, time expirations, "self destruction", highly controlled viewing areas, etc), making it more difficult for the recipient to "proove" you sent the information and show the information relying more on the recipients word, but even that has never been that secure (Snapchat is a simple example of such).