"Lambda is secure by default"
That is a high claim.
The only thing that is secure by default is a safe hidden in a salt mine behind a camouflaged brick wall that nobody knows is there and everyone involved in making it happen has been brought to a pit in another country and shot.
And those that did the shooting were brought to a pit in another country and shot.
Then the person having orchestrated all this took a poison pill and died.
THAT is secure by default.
The rest is just guardrails surfing on hope.