Trust by default.
Every system decides, before it meets you, what kind of person you probably are. Most guess badly.
A gate charges everyone to stop a few.
Suspicion feels free because its cost never lands on the person who chose it. It lands on the honest majority, in small amounts, forever: the forgotten password at the worst moment, the receipt kept for a refund that was never in doubt, the signature on a purchase smaller than the time spent approving it. Each one is trivial. Together they are most of what makes dealing with institutions feel like being accused of something.
A rule aimed at the rare bad actor is a rule aimed mostly at everyone else, because everyone else is who shows up. Determined people route around gates. That is the definition of determined.
This page decided the other way.
The sentence below was written by the last person who came through here. Nobody checked who they were. Nobody will check who you are.
Every version is kept. Any of them can be put back.
It is yours now, if you want it. Change a word, or all of them, and the next stranger will read what you left. Nothing on this page will ask you to prove anything first.
Move the check behind the action, not in front of it.
Trust by default is not the absence of enforcement. It is enforcement placed after the fact, where it can be aimed at the person who actually did something, rather than before the fact, where it can only be aimed at everyone. The practical question is never trust or verify. It is when, and who pays for the timing.
The assumption is only safe when the system around it has certain properties. Make harm reversible before you make entry easy: an edit with history is safe to open, a wire transfer is not. Cap the blast radius, not the entrance: let anyone in, and limit what any single arrival can affect. Keep the record open in both directions. Respond to evidence, never to category. Make the exit as easy as the entry. Count the losses out loud.
That is what holds the sentence above. One visitor can change one sentence, not the page. Links and markup are refused. A visitor who changes it forty times in a day is asked to wait, quietly, after the fortieth, not before the first. Every version is kept where anyone can read it, and any of them can be put back by anyone. The vandalism is not prevented. It is made reversible, which is cheaper, and which is the argument.
It already works.
An encyclopedia let anyone edit any page and became the most consulted reference in human history. Package registries let anyone publish. Most open source projects accept a change from a stranger who has never proved anything except that the change was good. Every one of them absorbs abuse. Every one of them has editors, revert buttons and revocation. The front is open; the back is strong. The systems built on suspicion are not obviously safer. They are just smaller, slower and worse to be inside.
Any system that greets you with a test has told you its answer already.